draft-ietf-mpls-mpls-and-gmpls-security-framework-04.txt   draft-ietf-mpls-mpls-and-gmpls-security-framework-05.txt 
Network Working Group Luyuan Fang, Ed. Network Working Group Luyuan Fang, Ed.
Internet Draft Cisco Systems, Inc. Internet Draft Cisco Systems, Inc.
Category: Informational Category: Informational
November 2, 2008 Expires: September 10, 2009
March 9, 2009
Security Framework for MPLS and GMPLS Networks Security Framework for MPLS and GMPLS Networks
draft-ietf-mpls-mpls-and-gmpls-security-framework-04.txt draft-ietf-mpls-mpls-and-gmpls-security-framework-05.txt
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Abstract Abstract
This document provides a security framework for Multiprotocol Label This document provides a security framework for Multiprotocol Label
Switching (MPLS) and Generalized Multiprotocol Label Switching Switching (MPLS) and Generalized Multiprotocol Label Switching
(GMPLS) Networks (MPLS and GMPLS are described in [RFC3031] and (GMPLS) Networks (MPLS and GMPLS are described in [RFC3031] and
[RFC3945]). This document addresses the security aspects that are [RFC3945]). This document addresses the security aspects that are
relevant in the context of MPLS and GMPLS. It describes the relevant in the context of MPLS and GMPLS. It describes the
security threats, the related defensive techniques, and the security threats, the related defensive techniques, and the
mechanisms for detection and reporting. This document emphasizes mechanisms for detection and reporting. This document emphasizes
RSVP-TE and LDP security considerations, as well as Inter-AS and RSVP-TE and LDP security considerations, as well as Inter-AS and
Inter-provider security considerations for building and maintaining Inter-provider security considerations for building and maintaining
MPLS and GMPLS networks across different domains or different MPLS and GMPLS networks across different domains or different
Service Providers. Service Providers.
MPLS/GMPLS Security framework
November 2008
Table of Contents Table of Contents
1. Introduction..................................................3 1. Introduction..................................................3
1.1. Structure of this Document.................................4 1.1. Structure of this Document.................................4
1.2. Authors and Contributors...................................4 1.2. Authors and Contributors...................................5
2. Terminology...................................................5 2. Terminology...................................................5
2.1. Terminology................................................5 2.1. Terminology................................................5
2.2. Acronyms and Abbreviations.................................7 2.2. Acronyms and Abbreviations.................................7
3. Security Reference Models.....................................8 3. Security Reference Models.....................................8
4. Security Threats.............................................10 4. Security Threats.............................................10
4.1. Attacks on the Control Plane..............................11 4.1. Attacks on the Control Plane..............................11
4.2. Attacks on the Data Plane.................................14 4.2. Attacks on the Data Plane.................................15
5. Defensive Techniques for MPLS/GMPLS Networks.................16 5. Defensive Techniques for MPLS/GMPLS Networks.................17
5.1. Authentication............................................17 5.1. Authentication............................................18
5.2. Cryptographic Techniques..................................19 5.2. Cryptographic Techniques..................................20
5.3. Access Control Techniques.................................29 5.3. Access Control Techniques.................................29
5.4. Use of Isolated Infrastructure............................33 5.4. Use of Isolated Infrastructure............................34
5.5. Use of Aggregated Infrastructure..........................34 5.5. Use of Aggregated Infrastructure..........................35
5.6. Service Provider Quality Control Processes................34 5.6. Service Provider Quality Control Processes................35
5.7. Deployment of Testable MPLS/GMPLS Service.................35 5.7. Deployment of Testable MPLS/GMPLS Service.................36
5.8. Verification of Connectivity..............................35 5.8. Verification of Connectivity..............................36
6. Monitoring, Detection, and Reporting of Security Attacks.....35
7. Service Provider General Security Requirements...............36
7.1. Protection within the Core Network........................37
7.2. Protection on the User Access Link........................40
7.3. General User Requirements for MPLS/GMPLS Providers........42
8. Inter-provider Security Requirements.........................43
8.1. Control Plane Protection..................................43
8.2. Data Plane Protection.....................................47
9. Summary of MPLS and GMPLS Security...........................49
9.1. MPLS and GMPLS Specific Security Threats..................49
9.2. Defense Techniques........................................50
9.3. Service Provider MPLS and GMPLS Best Practice Outlines....50
10. Security Considerations....................................51
11. IANA Considerations........................................52
12. Normative References.......................................52
13. Informational References...................................53
14. Author's Addresses.........................................55
15. Acknowledgements...........................................57
MPLS/GMPLS Security framework MPLS/GMPLS Security framework
November 2008 6. Monitoring, Detection, and Reporting of Security Attacks.....36
7. Service Provider General Security Requirements...............37
7.1. Protection within the Core Network........................38
7.2. Protection on the User Access Link........................42
7.3. General User Requirements for MPLS/GMPLS Providers........43
8. Inter-provider Security Requirements.........................44
8.1. Control Plane Protection..................................44
8.2. Data Plane Protection.....................................48
9. Summary of MPLS and GMPLS Security...........................50
9.1. MPLS and GMPLS Specific Security Threats..................50
9.2. Defense Techniques........................................51
9.3. Service Provider MPLS and GMPLS Best Practice Outlines....51
10. Security Considerations....................................52
11. IANA Considerations........................................53
12. Normative References.......................................53
13. Informative References.....................................55
14. Author's Addresses.........................................56
15. Acknowledgements...........................................58
Conventions used in this document Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
this document are to be interpreted as described in RFC2119 [RFC this document are to be interpreted as described in RFC2119 [RFC
2119]. 2119].
1. Introduction 1. Introduction
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RFCs on MPLS and GMPLS technologies, but no single document covers RFCs on MPLS and GMPLS technologies, but no single document covers
general security considerations. The motivation for creating this general security considerations. The motivation for creating this
document is to provide a comprehensive and consistent security document is to provide a comprehensive and consistent security
framework for MPLS and GMPLS networks. Each individual document may framework for MPLS and GMPLS networks. Each individual document may
point to this document for general security considerations in point to this document for general security considerations in
addition to providing security considerations specific to the addition to providing security considerations specific to the
particular technologies the document is describing. particular technologies the document is describing.
In this document, we first describe the security threats relevant In this document, we first describe the security threats relevant
in the context of MPLS and GMPLS and the defensive techniques to in the context of MPLS and GMPLS and the defensive techniques to
combat those threats. We consider security issues deriving both MPLS/GMPLS Security framework
combat those threats. We consider security issues resulting both
from malicious or incorrect behavior of users and other parties and from malicious or incorrect behavior of users and other parties and
from negligent or incorrect behavior of providers. An important from negligent or incorrect behavior of providers. An important
part of security defense is the detection and reporting of a part of security defense is the detection and reporting of a
security attack, which is also addressed in this document. security attack, which is also addressed in this document.
We then discuss possible service provider security requirements in We then discuss possible service provider security requirements in
a MPLS or GMPLS environment. Users have expectations for the a MPLS or GMPLS environment. Users have expectations for the
security characteristics of MPLS or GMPLS networks. These include security characteristics of MPLS or GMPLS networks. These include
security requirements for equipment supporting MPLS and GMPLS and security requirements for equipment supporting MPLS and GMPLS and
operational security requirements for providers. Service providers operational security requirements for providers. Service providers
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level required to provide services over their MPLS or GMPLS level required to provide services over their MPLS or GMPLS
networks. networks.
Inter-AS and Inter-provider security are discussed with special Inter-AS and Inter-provider security are discussed with special
emphasis, because the security risk factors are higher with inter- emphasis, because the security risk factors are higher with inter-
provider connections. provider connections.
Depending on different MPLS or GMPLS techniques used, the degree of Depending on different MPLS or GMPLS techniques used, the degree of
risk and the mitigation methodologies vary. This document discusses risk and the mitigation methodologies vary. This document discusses
the security aspects and requirements for certain basic MPLS and the security aspects and requirements for certain basic MPLS and
MPLS/GMPLS Security framework
November 2008
GMPLS techniques and inter-connection models. This document does GMPLS techniques and inter-connection models. This document does
not attempt to cover all current and future MPLS and GMPLS not attempt to cover all current and future MPLS and GMPLS
technologies, as it is not within the scope of this document to technologies, as it is not within the scope of this document to
analyze the security properties of specific technologies. analyze the security properties of specific technologies.
It is important to clarify that, in this document, we limit It is important to clarify that, in this document, we limit
ourselves to describing the providers' security requirements that ourselves to describing the providers' security requirements that
pertain to MPLS and GMPLS networks. Readers may refer to the pertain to MPLS and GMPLS networks. Readers may refer to the
"Security Best Practices Efforts and Documents" [opsec effort] and "Security Best Practices Efforts and Documents" [opsec effort] and
"Security Mechanisms for the Internet" [RFC3631] for general "Security Mechanisms for the Internet" [RFC3631] for general
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This document is organized as follows. In Section 2, we define the This document is organized as follows. In Section 2, we define the
terminology used. In Section 3, we define the security reference terminology used. In Section 3, we define the security reference
models for security in MPLS/GMPLS networks, which we use in the models for security in MPLS/GMPLS networks, which we use in the
rest of the document. In Section 4, we describe the security rest of the document. In Section 4, we describe the security
threats specific to MPLS and GMPLS. In Section 5, we review threats specific to MPLS and GMPLS. In Section 5, we review
defensive techniques that may be used against those threats. In defensive techniques that may be used against those threats. In
Section 6, we describe how attacks may be detected and reported. In Section 6, we describe how attacks may be detected and reported. In
Section 7, we describe security requirements providers may have to Section 7, we describe security requirements providers may have to
guarantee the security of the network infrastructure for MPLS/GMPLS guarantee the security of the network infrastructure for MPLS/GMPLS
MPLS/GMPLS Security framework
services. In section 8, we discuss Inter-provider security services. In section 8, we discuss Inter-provider security
requirements. Finally, in Section 9, we discuss security requirements. Finally, in Section 9, we discuss security
considerations for this document. considerations for this document.
This document has used relevant content from RFC 4111 "Security This document has used relevant content from RFC 4111 "Security
Framework of Provider Provisioned VPN for Provider-Provisioned Framework of Provider Provisioned VPN for Provider-Provisioned
Virtual Private Networks (PPVPNs)" [RFC4111], and "MPLS Virtual Private Networks (PPVPNs)" [RFC4111], and "MPLS
InterCarrier Interconnect Technical Specification" [MFA MPLS ICI] InterCarrier Interconnect Technical Specification" [MFA MPLS ICI]
in the Inter-provider security discussion. We acknowledge the in the Inter-provider security discussion. We acknowledge the
authors of these documents for the valuable information and text. authors of these documents for the valuable information and text.
1.2. Authors and Contributors 1.2. Authors and Contributors
Authors: Authors:
Luyuan Fang, Ed., Cisco Systems, Inc. Luyuan Fang, Ed., Cisco Systems, Inc.
Michael Behringer, Cisco Systems, Inc. Michael Behringer, Cisco Systems, Inc.
Ross Callon, Juniper Networks Ross Callon, Juniper Networks
Richard Graveman, RFG Security, LLC
J. L. Le Roux, France Telecom J. L. Le Roux, France Telecom
Raymond Zhang, British Telecom Raymond Zhang, British Telecom
Paul Knight, Nortel Paul Knight, Individual Contributor
Yaakov Stein, RAD Data Communications Yaakov Stein, RAD Data Communications
MPLS/GMPLS Security framework
November 2008
Nabil Bitar, Verizon Nabil Bitar, Verizon
Richard Graveman, RFC Security, LLC
Monique Morrow, Cisco Systems, Inc. Monique Morrow, Cisco Systems, Inc.
Adrian Farrel, Old Dog Consulting Adrian Farrel, Old Dog Consulting
As a design team member for the MPLS Security Framework, Jerry Ash As a design team member for the MPLS Security Framework, Jerry Ash
also made significant contributions to this document. also made significant contributions to this document.
2. Terminology 2. Terminology
2.1. Terminology 2.1. Terminology
This document uses MPLS and GMPLS specific terminology. Definitions This document uses MPLS and GMPLS specific terminology. Definitions
and details about MPLS and GMPLS terminology can be found in and details about MPLS and GMPLS terminology can be found in
[RFC3031] and [RFC3945]. The most important definitions are [RFC3031] and [RFC3945]. The most important definitions are
repeated in this section; for other definitions the reader is repeated in this section; for other definitions the reader is
referred to [RFC3031] and [RFC3945]. referred to [RFC3031] and [RFC3945].
Core network: A MPLS/GMPLS core network is defined as the central
network infrastructure which consists of P and PE routers. A
MPLS/GMPLS core network may consist of one or more networks
belonging to a single SP.
MPLS/GMPLS Security framework
Customer Edge (CE) device: A Customer Edge device is a router or a Customer Edge (CE) device: A Customer Edge device is a router or a
switch in the customer's network interfacing with the Service switch in the customer's network interfacing with the Service
Provider's network. Provider's network.
Forwarding Equivalence Class (FEC): A group of IP packets that are Forwarding Equivalence Class (FEC): A group of IP packets that are
forwarded in the same manner (e.g., over the same path, with the forwarded in the same manner (e.g., over the same path, with the
same forwarding treatment). same forwarding treatment).
Label: A short, fixed length, physically contiguous identifier used Label: A short, fixed length, physically contiguous identifier used
to identify a FEC, usually of local significance. to identify a FEC, usually of local significance.
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Label Switching Router (LSR): An MPLS node capable of forwarding Label Switching Router (LSR): An MPLS node capable of forwarding
native IP packets. native IP packets.
Loop Detection: A method of dealing with loops in which loops are Loop Detection: A method of dealing with loops in which loops are
allowed to be set up, and data may be transmitted over the loop, allowed to be set up, and data may be transmitted over the loop,
but the loop is later detected. but the loop is later detected.
Loop Prevention: A method of dealing with loops in which data is Loop Prevention: A method of dealing with loops in which data is
never transmitted over a loop. never transmitted over a loop.
MPLS/GMPLS Security framework
November 2008
Label Stack: An ordered set of labels. Label Stack: An ordered set of labels.
Merge Point: A node at which label merging is done. Merge Point: A node at which label merging is done.
MPLS Domain: A contiguous set of nodes that perform MPLS routing MPLS Domain: A contiguous set of nodes that perform MPLS routing
and forwarding and are also in one Routing or Administrative and forwarding and are also in one Routing or Administrative
Domain. Domain.
MPLS Edge Node: A MPLS node that connects a MPLS domain with a node MPLS Edge Node: A MPLS node that connects a MPLS domain with a node
outside of the domain, either because it does not run MPLS, or outside of the domain, either because it does not run MPLS, or
because it is in a different domain. Note that if a LSR has a because it is in a different domain. Note that if a LSR has a
neighboring host not running MPLS, then that LSR is a MPLS edge neighboring host not running MPLS, then that LSR is a MPLS edge
node. node.
MPLS Egress Node: A MPLS edge node in its role in handling traffic MPLS Egress Node: A MPLS edge node in its role in handling traffic
as it leaves a MPLS domain. as it leaves a MPLS domain.
MPLS Ingress Node: A MPLS edge node in its role in handling traffic MPLS Ingress Node: A MPLS edge node in its role in handling traffic
as it enters a MPLS domain. as it enters a MPLS domain.
MPLS/GMPLS Security framework
MPLS Label: A label carried in a packet header, which represents MPLS Label: A label carried in a packet header, which represents
the packet's FEC. the packet's FEC.
MPLS Node: A node running MPLS. A MPLS node is aware of MPLS MPLS Node: A node running MPLS. A MPLS node is aware of MPLS
control protocols, runs one or more routing protocols, and is control protocols, runs one or more routing protocols, and is
capable of forwarding packets based on labels. A MPLS node may capable of forwarding packets based on labels. A MPLS node may
optionally be also capable of forwarding native IP packets. optionally be also capable of forwarding native IP packets.
MultiProtocol Label Switching (MPLS): An IETF working group and the MultiProtocol Label Switching (MPLS): An IETF working group and the
effort associated with the working group. effort associated with the working group.
P: Provider Router. A Provider Router is a router in the Service P: Provider Router. A Provider Router is a router in the Service
Provider's core network that does not have interfaces directly Provider's core network that does not have interfaces directly
towards the customer. A P router is used to interconnect the PE towards the customer. A P router is used to interconnect the PE
routers. routers.
PE: Provider Edge device. A Provider Edge device is the equipment PE: Provider Edge device. A Provider Edge device is the equipment
in the Service Provider's network that interfaces with the in the Service Provider's network that interfaces with the
equipment in the customer's network. equipment in the customer's network.
Core network: A MPLS/GMPLS core network is defined as the central
network infrastructure which consists of P and PE routers. A
MPLS/GMPLS core network may consist of one or more networks belong
to a single SP.
VPN: Virtual Private Network, which restricts communication between VPN: Virtual Private Network, which restricts communication between
a set of sites, making use of an IP backbone shared by traffic not a set of sites, making use of an IP backbone shared by traffic not
going to or not coming from those sites ([RFC4110]). going to or not coming from those sites ([RFC4110]).
MPLS/GMPLS Security framework
November 2008
2.2. Acronyms and Abbreviations 2.2. Acronyms and Abbreviations
AS Autonomous System AS Autonomous System
ASBR Autonomous System Border Router ASBR Autonomous System Border Router
ATM Asynchronous Transfer Mode ATM Asynchronous Transfer Mode
BGP Border Gateway Protocol BGP Border Gateway Protocol
BFD Bidirectional Forwarding Detection BFD Bidirectional Forwarding Detection
CE Customer-Edge device CE Customer-Edge device
CoS Class of Service CoS Class of Service
CPU Central Processor Unit CPU Central Processing Unit
DNS Domain Name System DNS Domain Name System
DoS Denial of Service DoS Denial of Service
ESP Encapsulating Security Payload
FEC Forwarding Equivalence Class FEC Forwarding Equivalence Class
GMPLS Generalized Multi-Protocol Label Switching GMPLS Generalized Multi-Protocol Label Switching
GCM Galois Counter Mode
GRE Generic Routing Encapsulation GRE Generic Routing Encapsulation
ICI InterCarrier Interconnect ICI InterCarrier Interconnect
ICMP Internet Control Message Protocol ICMP Internet Control Message Protocol
ICMPv6 ICMP in IP Version 6 ICMPv6 ICMP in IP Version 6
IGP Interior Gateway Protocol IGP Interior Gateway Protocol
IKE Internet Key Exchange IKE Internet Key Exchange
IP Internet Protocol IP Internet Protocol
IPsec IP Security IPsec IP Security
MPLS/GMPLS Security framework
IPVPN IP-based VPN IPVPN IP-based VPN
LDP Label Distribution Protocol LDP Label Distribution Protocol
L2TP Layer 2 Tunneling Protocol L2TP Layer 2 Tunneling Protocol
LMP Link Management Protocol LMP Link Management Protocol
LSP Label Switched Path LSP Label Switched Path
LSR Label Switching Router LSR Label Switching Router
MD5 Message Digest Algorithm MD5 Message Digest Algorithm
MPLS MultiProtocol Label Switching MPLS MultiProtocol Label Switching
MP-BGP Multi-Protocol BGP MP-BGP Multi-Protocol BGP
NTP Network Time Protocol NTP Network Time Protocol
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PW Pseudowire PW Pseudowire
QoS Quality of Service QoS Quality of Service
RR Route Reflector RR Route Reflector
RSVP Resource Reservation Protocol RSVP Resource Reservation Protocol
RSVP-TE Resource Reservation Protocol with Traffic Engineering RSVP-TE Resource Reservation Protocol with Traffic Engineering
Extensions Extensions
SLA Service Level Agreement SLA Service Level Agreement
SNMP Simple Network Management Protocol SNMP Simple Network Management Protocol
SP Service Provider SP Service Provider
SSH Secure Shell SSH Secure Shell
MPLS/GMPLS Security framework
November 2008
SSL Secure Sockets Layer SSL Secure Sockets Layer
SYN Synchronize packet in TCP SYN Synchronize packet in TCP
TCP Transmission Control Protocol TCP Transmission Control Protocol
TDM Time Division Multiplexing TDM Time Division Multiplexing
TE Traffic Engineering TE Traffic Engineering
TLS Transport Layer Security TLS Transport Layer Security
ToS Type of Service ToS Type of Service
TTL Time-To-Live TTL Time-To-Live
UDP User Datagram Protocol UDP User Datagram Protocol
VC Virtual Circuit VC Virtual Circuit
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WG Working Group of IETF WG Working Group of IETF
WSS Web Services Security WSS Web Services Security
3. Security Reference Models 3. Security Reference Models
This section defines a reference model for security in MPLS/GMPLS This section defines a reference model for security in MPLS/GMPLS
networks. networks.
This document defines each MPLS/GMPLS core in a single domain to be This document defines each MPLS/GMPLS core in a single domain to be
a trusted zone. A primary concern is about security aspects that a trusted zone. A primary concern is about security aspects that
relate to breaches of security from the "outside" of a trusted zone relate to breaches of security from the "outside" of a trusted zone
MPLS/GMPLS Security framework
to the "inside" of this zone. Figure 1 depicts the concept of to the "inside" of this zone. Figure 1 depicts the concept of
trusted zones within the MPLS/GMPLS framework. trusted zones within the MPLS/GMPLS framework.
/-------------\ /-------------\
+------------+ / \ +------------+ +------------+ / \ +------------+
| MPLS/GMPLS +---/ \--------+ MPLS/GMPLS | | MPLS/GMPLS +---/ \--------+ MPLS/GMPLS |
| user | MPLS/GMPLS Core | user | | user | MPLS/GMPLS Core | user |
| site +---\ /XXX-----+ site | | site +---\ /XXX-----+ site |
+------------+ \ / XXX +------------+ +------------+ \ / XXX +------------+
\-------------/ | | \-------------/ | |
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+--------/ "Internet" +--------/ "Internet"
MPLS/GMPLS Core with user connections and Internet connection MPLS/GMPLS Core with user connections and Internet connection
Figure 1: The MPLS/GMPLS trusted zone model. Figure 1: The MPLS/GMPLS trusted zone model.
The trusted zone is the MPLS/GMPLS core in a single AS within a The trusted zone is the MPLS/GMPLS core in a single AS within a
single Service Provider. single Service Provider.
The boundaries of a trust domain should be carefully defined when The boundaries of a trust domain should be carefully defined when
analyzing the security property of each individual network, e.g., analyzing the security properties of each individual network, e.g.,
MPLS/GMPLS Security framework
November 2008
the boundaries can be at the link termination, remote peers, areas, the boundaries can be at the link termination, remote peers, areas,
or quite commonly, ASes. or quite commonly, ASes.
In principle, the trusted zones should be separate; however, In principle, the trusted zones should be separate; however,
typically MPLS core networks also offer Internet access, in which typically MPLS core networks also offer Internet access, in which
case a transit point (marked with "XXX" in Figure 1) is defined. In case a transit point (marked with "XXX" in Figure 1) is defined. In
the case of MPLS/GMPLS inter-provider connections, the trusted zone the case of MPLS/GMPLS inter-provider connections, the trusted zone
of each provider ends at the respective ASBRs (ASBR1 and ASBR2 for of each provider ends at the respective ASBRs (ASBR1 and ASBR2 for
Provider A, ASBR3 and ASBR4 for Provider B). Provider A and ASBR3 and ASBR4 for Provider B in Figure 2).
A key requirement of MPLS and GMPLS networks is that the security A key requirement of MPLS and GMPLS networks is that the security
of the trusted zone not be compromised by interconnecting the of the trusted zone not be compromised by interconnecting the
MPLS/GMPLS core infrastructure with another provider's core MPLS/GMPLS core infrastructure with another provider's core
(MPLS/GMPLS or non-MPLS/GMPLS), the Internet, or end users. (MPLS/GMPLS or non-MPLS/GMPLS), the Internet, or end users.
In addition, neighbors may be trusted or untrusted. Neighbors may In addition, neighbors may be trusted or untrusted. Neighbors may
be authorized or unauthorized. Even though a neighbor may be be authorized or unauthorized. Even though a neighbor may be
authorized for communication, it may not be trusted. For example, authorized for communication, it may not be trusted. For example,
when connecting with another provider's ASBRs to set up inter-AS when connecting with another provider's ASBRs to set up inter-AS
LSPs, the other provider is considered an untrusted but authorized LSPs, the other provider is considered an untrusted but authorized
neighbor. neighbor.
MPLS/GMPLS Security framework
+---------------+ +----------------+ +---------------+ +----------------+
| | | | | | | |
| MPLS/GMPLS ASBR1----ASBR3 MPLS/GMPLS | | MPLS/GMPLS ASBR1----ASBR3 MPLS/GMPLS |
CE1--PE1 Network | | Network PE2--CE2 CE1--PE1 Network | | Network PE2--CE2
| Provider A ASBR2----ASBR4 Provider B | | Provider A ASBR2----ASBR4 Provider B |
| | | | | | | |
+---------------+ +----------------+ +---------------+ +----------------+
For Provider A: For Provider A:
Trusted Zone: Provider A MPSL/GMPLS network Trusted Zone: Provider A MPSL/GMPLS network
skipping to change at page 10, line 5 skipping to change at page 10, line 29
Figure 2. MPLS/GMPLS trusted zone and authorized neighbor. Figure 2. MPLS/GMPLS trusted zone and authorized neighbor.
All aspects of network security independent of whether a network is All aspects of network security independent of whether a network is
a MPLS/GMPLS network are out of scope. For example, attacks from a MPLS/GMPLS network are out of scope. For example, attacks from
the Internet to a user's web-server connected through the the Internet to a user's web-server connected through the
MPLS/GMPLS network are not considered here, unless the way the MPLS/GMPLS network are not considered here, unless the way the
MPLS/GMPLS network is provisioned could make a difference to the MPLS/GMPLS network is provisioned could make a difference to the
security of this user's server. security of this user's server.
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4. Security Threats 4. Security Threats
This section discusses the various network security threats that This section discusses the various network security threats that
may endanger MPLS/GMPLS networks. The discussion is limited to may endanger MPLS/GMPLS networks. The discussion is limited to
those threats that are unique to MPLS/GMPLS networks or that affect those threats that are unique to MPLS/GMPLS networks or that affect
MPLS/GMPLS network in unique ways. MPLS/GMPLS network in unique ways.
A successful attack on a particular MPLS/GMPLS network or on a SP's A successful attack on a particular MPLS/GMPLS network or on a SP's
MPLS/GMPLS infrastructure may cause one or more of the following MPLS/GMPLS infrastructure may cause one or more of the following
ill effects: ill effects:
- Observation, modification, or deletion of a provider's or user's - Observation, modification, or deletion of a provider's or user's
data. data.
- Replay of a provider's or user's data. - Replay of a provider's or user's data.
- Injection of inauthentic data into a provider's or user's - Injection of inauthentic data into a provider's or user's
traffic stream. traffic stream.
- Traffic pattern analysis on a provider's or user's traffic. - Traffic pattern analysis on a provider's or user's traffic.
- Disruption of a provider's or user's connectivity. - Disruption of a provider's or user's connectivity.
- Degradation of a provider's service quality. - Degradation of a provider's service quality.
- Probing a provider's network to determine its configutation,
capacity, or usage.
MPLS/GMPLS Security framework
It is useful to consider that threats, whether malicious or It is useful to consider that threats, whether malicious or
accidental, may come from different categories of sources. For accidental, may come from different categories of sources. For
example they may come from: example they may come from:
- Other users whose services are provided by the same MPLS/GMPLS - Other users whose services are provided by the same MPLS/GMPLS
core. core.
- The MPLS/GMPLS SP or persons working for it. - The MPLS/GMPLS SP or persons working for it.
- Other persons who obtain physical access to a MPLS/GMPLS SP's - Other persons who obtain physical access to a MPLS/GMPLS SP's
site. site.
- Other persons who use social engineering methods to influence - Other persons who use social engineering methods to influence
the behavior of a SP's personnel. the behavior of a SP's personnel.
- Users of the MPLS/GMPLS network itself, e.g., intra-VPN threats. - Users of the MPLS/GMPLS network itself, e.g., intra-VPN threats.
(Such threats are beyond the scope of this document.) (Such threats are beyond the scope of this document.)
- Others, e.g., attackers from the Internet at large. - Others, e.g., attackers from the Internet at large.
- Other SPs in the case of MPLS/GMPLS Inter- - Other SPs in the case of MPLS/GMPLS Inter-provider connection.
provider connection. The core of the other provider may or may The core of the other provider may or may not be using
not be using MPLS/GMPLS. MPLS/GMPLS.
- Those who create, deliver, install, and maintain software for - Those who create, deliver, install, and maintain software for
network equipment. network equipment.
Given that security is generally a tradeoff between expense and Given that security is generally a tradeoff between expense and
risk, it is also useful to consider the likelihood of different risk, it is also useful to consider the likelihood of different
attacks occurring. There is at least a perceived difference in the attacks occurring. There is at least a perceived difference in the
likelihood of most types of attacks being successfully mounted in likelihood of most types of attacks being successfully mounted in
different environments, such as: different environments, such as:
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- A MPLS/GMPLS core inter-connecting with another provider's core - A MPLS/GMPLS core inter-connecting with another provider's core
- A MPLS/GMPLS configuration transiting the public Internet - A MPLS/GMPLS configuration transiting the public Internet
Most types of attacks become easier to mount and hence more likely Most types of attacks become easier to mount and hence more likely
as the shared infrastructure via which service is provided expands as the shared infrastructure via which service is provided expands
from a single SP to multiple cooperating SPs to the global from a single SP to multiple cooperating SPs to the global
Internet. Attacks that may not be of sufficient likeliness to Internet. Attacks that may not be of sufficient likeliness to
warrant concern in a closely controlled environment often merit warrant concern in a closely controlled environment often merit
defensive measures in broader, more open environments. In closed defensive measures in broader, more open environments. In closed
communities, it is often practical to deal with misbehavior after communities, it is often practical to deal with misbehavior after
the fact: an employee can be disciplined, for example. the fact: an employee can be disciplined, for example.
The following sections discuss specific types of exploits that The following sections discuss specific types of exploits that
threaten MPLS/GMPLS networks. threaten MPLS/GMPLS networks.
4.1. Attacks on the Control Plane 4.1. Attacks on the Control Plane
This category encompasses attacks on the control structures This category encompasses attacks on the control structures
operated by the SP with MPLS/GMPLS cores. operated by the SP with MPLS/GMPLS cores.
MPLS/GMPLS Security framework
It should be noted that while connectivity in the MPLS control plane It should be noted that while connectivity in the MPLS control plane
uses the same links and network resources as are used by the data uses the same links and network resources as are used by the data
plane, the GMPLS control plane may be provided by separate resources plane, the GMPLS control plane may be provided by separate resources
from those used in the data plane. That is, the GMPLS control plane from those used in the data plane. That is, the GMPLS control plane
may be physically diverse from the data plane. may be physically separate from the data plane.
The different cases of physically congruent and physically diverse The different cases of physically congruent and physically separate
control/data planes lead to slightly different possibilities of control/data planes lead to slightly different possibilities of
attack, although most of the cases are the same. Note that, for attack, although most of the cases are the same. Note that, for
example, the data plane cannot be directly congested by an attack on example, the data plane cannot be directly congested by an attack on
a physically diverse control plane as it could be if the control and a physically separate control plane as it could be if the control
data planes shared network resources. Note also that if the control and data planes shared network resources. Note also that if the
plane uses diverse resources from the data plane, no assumptions control plane uses diverse resources from the data plane, no
should be made about the security of the control plane based on the assumptions should be made about the security of the control plane
security of the data plane resources. based on the security of the data plane resources.
4.1.1. LSP creation by an unauthorized element 4.1.1. LSP creation by an unauthorized element
The unauthorized element can be a local CE or a router in another The unauthorized element can be a local CE or a router in another
domain. An unauthorized element can generate MPLS signaling domain. An unauthorized element can generate MPLS signaling
messages. At the least, this can result in extra control plane and messages. At the least, this can result in extra control plane and
forwarding state, and if successful, network bandwidth could be forwarding state, and if successful, network bandwidth could be
reserved unnecessarily. This may also result in theft of service or reserved unnecessarily. This may also result in theft of service or
even compromise the entire network. even compromise the entire network.
4.1.2. LSP message interception 4.1.2. LSP message interception
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This threat might be accomplished by monitoring network traffic, This threat might be accomplished by monitoring network traffic,
for example, after a physical intrusion. Without physical for example, after a physical intrusion. Without physical
intrusion, it could be accomplished with an unauthorized software intrusion, it could be accomplished with an unauthorized software
modification. Also many technologies such as terrestrial microwave, modification. Also, many technologies such as terrestrial
satellite, or free-space optical could be intercepted without microwave, satellite, or free-space optical could be intercepted
physical intrusion. If successful, it could provide information without physical intrusion. If successful, it could provide
leading to label spoofing attacks. It also raises confidentiality information leading to label spoofing attacks. It also raises
issues. confidentiality issues.
4.1.3. Attacks against RSVP-TE 4.1.3. Attacks against RSVP-TE
RSVP-TE, described in [RFC3209], is the control protocol used to RSVP-TE, described in [RFC3209], is the control protocol used to
set up GMPLS and traffic engineered MPLS tunnels. set up GMPLS and traffic engineered MPLS tunnels.
There are two major types of Denial of Service (DoS) attacks There are two major types of Denial of Service (DoS) attacks
against a MPLS domain based on RSVP-TE. The attacker may set up against a MPLS domain based on RSVP-TE. The attacker may set up
numerous unauthorized LSPs or may send a storm of RSVP messages. numerous unauthorized LSPs or may send a storm of RSVP messages.
It has been demonstrated that unprotected routers running RSVP can It has been demonstrated that unprotected routers running RSVP can
be effectively disabled by both types of DoS attacks. be effectively disabled by both types of DoS attacks.
MPLS/GMPLS Security framework
These attacks may even be combined, by using the unauthorized LSPs These attacks may even be combined, by using the unauthorized LSPs
to transport additional RSVP (or other) messages across routers to transport additional RSVP (or other) messages across routers
where they might otherwise be filtered out. RSVP attacks can be where they might otherwise be filtered out. RSVP attacks can be
launched against adjacent routers at the border with the attacker, launched against adjacent routers at the border with the attacker,
or against non-adjacent routers within the MPLS domain, if there is or against non-adjacent routers within the MPLS domain, if there is
no effective mechanism to filter them out. no effective mechanism to filter them out.
4.1.4. Attacks against LDP 4.1.4. Attacks against LDP
LDP, described in [RFC5036], is the control protocol used to set up LDP, described in [RFC5036], is the control protocol used to set up
MPLS tunnels without TE. MPLS tunnels without TE.
There are two significant types of attack against LDP. An There are two significant types of attack against LDP. An
unauthorized network element can establish a LDP session by sending unauthorized network element can establish a LDP session by sending
LDP Hello and LDP Init messages, leading to the potential setup of LDP Hello and LDP Init messages, leading to the potential setup of
a LSP, as well as accompanying LDP state table consumption. Even a LSP, as well as accompanying LDP state table consumption. Even
without successfully establishing LSPs, an attacker can launch a without successfully establishing LSPs, an attacker can launch a
DoS attack in the form of a storm of LDP Hello messages or LDP TCP DoS attack in the form of a storm of LDP Hello messages or LDP TCP
Syn messages, leading to high CPU utilization on the target router. SYN messages, leading to high CPU utilization or table space
exhaustion on the target router.
4.1.5. Denial of Service Attacks on the Network 4.1.5. Denial of Service Attacks on the Network
Infrastructure Infrastructure
DoS attacks could be accomplished through a MPLS signaling storm, DoS attacks could be accomplished through a MPLS signaling storm,
resulting in high CPU utilization and possibly leading to control resulting in high CPU utilization and possibly leading to control
plane resource starvation. plane resource starvation.
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Control plane DoS attacks can be mounted specifically against the Control plane DoS attacks can be mounted specifically against the
mechanisms the SP uses to provide various services, or against the mechanisms the SP uses to provide various services, or against the
general infrastructure of the service provider, e.g., P routers or general infrastructure of the service provider, e.g., P routers or
shared aspects of PE routers. (An attack against the general shared aspects of PE routers. (An attack against the general
infrastructure is within the scope of this document only if the infrastructure is within the scope of this document only if the
attack can occur in relation with the MPLS/GMPLS infrastructure; attack can occur in relation with the MPLS/GMPLS infrastructure;
otherwise is not a MPLS/GMPLS-specific issue.) otherwise is not a MPLS/GMPLS-specific issue.)
The attacks described in the following sections may each have The attacks described in the following sections may each have
denial of service as one of their effects. Other DoS attacks are denial of service as one of their effects. Other DoS attacks are
also possible. also possible.
4.1.6. Attacks on the SP's MPLS/GMPLS Equipment via 4.1.6. Attacks on the SP's MPLS/GMPLS Equipment via
Management Interfaces Management Interfaces
This includes unauthorized access to a SP's infrastructure This includes unauthorized access to a SP's infrastructure
equipment, for example to reconfigure the equipment or to extract equipment, for example to reconfigure the equipment or to extract
information (statistics, topology, etc.) pertaining to the network. information (statistics, topology, etc.) pertaining to the network.
MPLS/GMPLS Security framework
4.1.7. Social Engineering Attacks on the SP's 4.1.7. Social Engineering Attacks on the SP's
Infrastructure Infrastructure
Attacks in which the service provider network is reconfigured or Attacks in which the service provider's network is reconfigured or
damaged, or in which confidential information is improperly damaged, or in which confidential information is improperly
disclosed, may be mounted by manipulation of a SP's personnel. disclosed, may be mounted by manipulation of a SP's personnel.
These types of attacks are MPLS/GMPLS-specific if they affect These types of attacks are MPLS/GMPLS-specific if they affect
MPLS/GMPLS-serving mechanisms. MPLS/GMPLS-serving mechanisms.
4.1.8. Cross-Connection of Traffic between Users 4.1.8. Cross-Connection of Traffic between Users
This refers to the event in which expected isolation between This refers to the event in which expected isolation between
separate users (who may be VPN users) is breached. This includes separate users (who may be VPN users) is breached. This includes
cases such as: cases such as:
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- Two or more VPNs being improperly merged together - Two or more VPNs being improperly merged together
- A point-to-point VPN connecting the wrong two points - A point-to-point VPN connecting the wrong two points
- Any packet or frame being improperly delivered outside the VPN - Any packet or frame being improperly delivered outside the VPN
to which it belongs to which it belongs
Mis-connection or cross-connection of VPNs may be caused by service Mis-connection or cross-connection of VPNs may be caused by service
provider or equipment vendor error, or by the malicious action of provider or equipment vendor error, or by the malicious action of
an attacker. The breach may be physical (e.g., PE-CE links mis- an attacker. The breach may be physical (e.g., PE-CE links mis-
connected) or logical (e.g., improper device configuration). connected) or logical (e.g., improper device configuration).
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Anecdotal evidence suggests that the cross-connection threat is one Anecdotal evidence suggests that the cross-connection threat is one
of the largest security concerns of users (or would-be users). of the largest security concerns of users (or would-be users).
4.1.9. Attacks against Routing Protocols 4.1.9. Attacks against Routing Protocols
This encompasses attacks against underlying routing protocols that This encompasses attacks against underlying routing protocols that
are run by the SP and that directly support the MPLS/GMPLS core. are run by the SP and that directly support the MPLS/GMPLS core.
(Attacks against the use of routing protocols for the distribution (Attacks against the use of routing protocols for the distribution
of backbone routes are beyond the scope of this document.) of backbone routes are beyond the scope of this document.)
Specific attacks against popular routing protocols have been widely Specific attacks against popular routing protocols have been widely
studied and described in [RFC4593]. studied and described in [RFC4593].
4.1.10. Other Attacks on Control Traffic 4.1.10. Other Attacks on Control Traffic
Besides routing and management protocols (covered separately in the Besides routing and management protocols (covered separately in the
previous sections), a number of other control protocols may be previous sections), a number of other control protocols may be
directly involved in delivering services by the MPLS/GMPLS core. directly involved in delivering services by the MPLS/GMPLS core.
These include but may not be limited to: These include but may not be limited to:
MPLS/GMPLS Security framework
- MPLS signaling (LDP, RSVP-TE) discussed above in subsections - MPLS signaling (LDP, RSVP-TE) discussed above in subsections
4.1.4 and 4.1.3 4.1.4 and 4.1.3
- PCE signaling - PCE signaling
- IPsec signaling (IKE and IKEv2) - IPsec signaling (IKE and IKEv2)
- ICMP and ICMPv6 - ICMP and ICMPv6
- L2TP - L2TP
- BGP-based membership discovery - BGP-based membership discovery
- Database-based membership discovery (e.g., RADIUS) - Database-based membership discovery (e.g., RADIUS)
- Other protocols that may be important to the control - Other protocols that may be important to the control
infrastructure, e.g., DNS, LMP, NTP, SNMP, and GRE. infrastructure, e.g., DNS, LMP, NTP, SNMP, and GRE.
Attacks might subvert or disrupt the activities of these protocols, Attacks might subvert or disrupt the activities of these protocols,
for example via impersonation or DoS. for example via impersonation or DoS.
Note that all of the data plane attacks can also be done on the Note that all of the data plane attacks can also be carried out
packets of the control and management planes: insertion, spoofing, against the packets of the control and management planes:
replay, deletion, pattern analysis, and other attacks mentioned insertion, spoofing, replay, deletion, pattern analysis, and other
above. attacks mentioned above.
4.2. Attacks on the Data Plane 4.2. Attacks on the Data Plane
This category encompasses attacks on the provider's or end user's This category encompasses attacks on the provider's or end user's
data. Note that from the MPLS/GMPLS network end user's point of data. Note that from the MPLS/GMPLS network end user's point of
view, some of this might be control plane traffic, e.g. routing view, some of this might be control plane traffic, e.g. routing
protocols running from user site A to user site B via an IP or non- protocols running from user site A to user site B via IP or non-IP
IP connections, which may be some type of VPN. connections, which may be some type of VPN.
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4.2.1. Unauthorized Observation of Data Traffic 4.2.1. Unauthorized Observation of Data Traffic
This refers to "sniffing" provider or end user packets and This refers to "sniffing" provider or end user packets and
examining their contents. This can result in exposure of examining their contents. This can result in exposure of
confidential information. It can also be a first step in other confidential information. It can also be a first step in other
attacks (described below) in which the recorded data is modified attacks (described below) in which the recorded data is modified
and re-inserted, or simply replayed later. and re-inserted, or simply replayed later.
4.2.2. Modification of Data Traffic 4.2.2. Modification of Data Traffic
This refers to modifying the contents of packets as they traverse This refers to modifying the contents of packets as they traverse
the MPLS/GMPLS core. the MPLS/GMPLS core.
4.2.3. Insertion of Inauthentic Data Traffic: Spoofing 4.2.3. Insertion of Inauthentic Data Traffic: Spoofing
and Replay and Replay
Spoofing refers to sending a user or inserting into a data stream Spoofing refers to sending a user or inserting into a data stream
packets that do not belong, with the objective of having them packets that do not belong, with the objective of having them
accepted by the recipient as legitimate. Also included in this accepted by the recipient as legitimate. Also included in this
MPLS/GMPLS Security framework
category is the insertion of copies of once-legitimate packets that category is the insertion of copies of once-legitimate packets that
have been recorded and replayed. have been recorded and replayed.
4.2.4. Unauthorized Deletion of Data Traffic 4.2.4. Unauthorized Deletion of Data Traffic
This refers to causing packets to be discarded as they traverse the This refers to causing packets to be discarded as they traverse the
MPLS/GMPLS networks. This is a specific type of Denial of Service MPLS/GMPLS networks. This is a specific type of Denial of Service
attack. attack.
4.2.5. Unauthorized Traffic Pattern Analysis 4.2.5. Unauthorized Traffic Pattern Analysis
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4.2.6. Denial of Service Attacks 4.2.6. Denial of Service Attacks
Denial of Service (DoS) attacks are those in which an attacker Denial of Service (DoS) attacks are those in which an attacker
attempts to disrupt or prevent the use of a service by its attempts to disrupt or prevent the use of a service by its
legitimate users. Taking network devices out of service, modifying legitimate users. Taking network devices out of service, modifying
their configuration, or overwhelming them with requests for service their configuration, or overwhelming them with requests for service
are several of the possible avenues for DoS attack. are several of the possible avenues for DoS attack.
Overwhelming the network with requests for service, otherwise known Overwhelming the network with requests for service, otherwise known
as a "resource exhaustion" DoS attack, may target any resource in as a "resource exhaustion" DoS attack, may target any resource in
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the network, e.g., link bandwidth, packet forwarding capacity, the network, e.g., link bandwidth, packet forwarding capacity,
session capacity for various protocols, CPU power, table size, session capacity for various protocols, CPU power, table size,
storage overflows, and so on. storage overflows, and so on.
DoS attacks of the resource exhaustion type can be mounted against DoS attacks of the resource exhaustion type can be mounted against
the data plane of a particular provider or end user by attempting the data plane of a particular provider or end user by attempting
to insert (spoofing) an overwhelming quantity of inauthentic data to insert (spoofing) an overwhelming quantity of inauthentic data
into the provider or end user network from the outside of the into the provider or end user's network from the outside of the
trusted zone. Potential results might be to exhaust the bandwidth trusted zone. Potential results might be to exhaust the bandwidth
available to that provider or end user or to overwhelm the available to that provider or end user or to overwhelm the
cryptographic authentication mechanisms of the provider or end cryptographic authentication mechanisms of the provider or end
user. user.
Data plane resource exhaustion attacks can also be mounted by Data plane resource exhaustion attacks can also be mounted by
overwhelming the service provider's general (MPLS/GMPLS- overwhelming the service provider's general (MPLS/GMPLS-
independent) infrastructure with traffic. These attacks on the independent) infrastructure with traffic. These attacks on the
general infrastructure are not usually a MPLS/GMPLS-specific issue, general infrastructure are not usually a MPLS/GMPLS-specific issue,
unless the attack is mounted by another MPLS/GMPLS network user unless the attack is mounted by another MPLS/GMPLS network user
from a privileged position. (E.g., a MPLS/GMPLS network user might from a privileged position. (E.g., a MPLS/GMPLS network user might
MPLS/GMPLS Security framework
be able to monopolize network data plane resources and thus disrupt be able to monopolize network data plane resources and thus disrupt
other users.) other users.)
Many DoS attacks use amplification, whereby the attacker co-opts Many DoS attacks use amplification, whereby the attacker co-opts
otherwise innocent parties to increase the effect of the attack. otherwise innocent parties to increase the effect of the attack.
The attacker may, for example, send packets to a broadcast or The attacker may, for example, send packets to a broadcast or
multicast address with the spoofed source address of the victim, multicast address with the spoofed source address of the victim,
and all of the recipients may then respond to the victim. and all of the recipients may then respond to the victim.
4.2.7. Misconnection 4.2.7. Misconnection
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control plane. control plane.
In optical networks under GMPLS control, misconnection may give rise In optical networks under GMPLS control, misconnection may give rise
to physical safety risks as unprotected lasers may be activated to physical safety risks as unprotected lasers may be activated
without warning. without warning.
5. Defensive Techniques for MPLS/GMPLS Networks 5. Defensive Techniques for MPLS/GMPLS Networks
The defensive techniques discussed in this document are intended to The defensive techniques discussed in this document are intended to
describe methods by which some security threats can be addressed. describe methods by which some security threats can be addressed.
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November 2008
They are not intended as requirements for all MPLS/GMPLS They are not intended as requirements for all MPLS/GMPLS
implementations. The MPLS/GMPLS provider should determine the implementations. The MPLS/GMPLS provider should determine the
applicability of these techniques to the provider's specific applicability of these techniques to the provider's specific
service offerings, and the end user may wish to assess the value of service offerings, and the end user may wish to assess the value of
these techniques to the user's service requirements. The these techniques to the user's service requirements. The
operational environment determines the security requirements. operational environment determines the security requirements.
Therefore, protocol designers need to provide a full set of Therefore, protocol designers need to provide a full set of
security services, which can be used where appropriate. security services, which can be used where appropriate.
The techniques discussed here include encryption, authentication, The techniques discussed here include encryption, authentication,
filtering, firewalls, access control, isolation, aggregation, and filtering, firewalls, access control, isolation, aggregation, and
other techniques. others.
Often, security is achieved by careful protocol design, rather than Often, security is achieved by careful protocol design, rather than
by adding a security method. For example, one method of mitigating by adding a security method. For example, one method of mitigating
DoS attacks is to make sure that innocent parties cannot be used to DoS attacks is to make sure that innocent parties cannot be used to
amplify the attack. Security works better when it is "designed in" amplify the attack. Security works better when it is "designed in"
rather than "added on." rather than "added on."
MPLS/GMPLS Security framework
Nothing is ever 100% secure. Defense therefore involves protecting Nothing is ever 100% secure. Defense therefore involves protecting
against those attacks that are most likely to occur or that have against those attacks that are most likely to occur or that have
the most direct consequences if successful. For those attacks that the most direct consequences if successful. For those attacks that
are protected against, absolute protection is seldom achievable; are protected against, absolute protection is seldom achievable;
more often it is sufficient just to make the cost of a successful more often it is sufficient just to make the cost of a successful
attack greater than what the adversary will be willing or able to attack greater than what the adversary will be willing or able to
expend. expend.
Successfully defending against an attack does not necessarily mean Successfully defending against an attack does not necessarily mean
the attack must be prevented from happening or from reaching its the attack must be prevented from happening or from reaching its
target. In many cases the network can instead be designed to target. In many cases the network can instead be designed to
withstand the attack. For example, the introduction of inauthentic withstand the attack. For example, the introduction of inauthentic
packets could be defended against by preventing their introduction packets could be defended against by preventing their introduction
in the first place, or by making it possible to identify and in the first place, or by making it possible to identify and
eliminate them before delivery to the MPLS/GMPLS user's system. eliminate them before delivery to the MPLS/GMPLS user's system.
The latter is frequently a much easier task. The latter is frequently a much easier task.
5.1. Authentication 5.1. Authentication
To prevent security issues arising from some Denial-of-Service To prevent security issues arising from some DoS attacks or from
attacks or from malicious or accidental misconfiguration, it is malicious or accidental misconfiguration, it is critical that
critical that devices in the MPLS/GMPLS should only accept devices in the MPLS/GMPLS should only accept connections or control
connections or control messages from valid sources. Authentication messages from valid sources. Authentication refers to methods to
refers to methods to ensure that message sources are properly ensure that message sources are properly identified by the
identified by the MPLS/GMPLS devices with which they communicate. MPLS/GMPLS devices with which they communicate. This section
This section focuses on identifying the scenarios in which sender focuses on identifying the scenarios in which sender authentication
authentication is required and recommends authentication mechanisms is required and recommends authentication mechanisms for these
for these scenarios. scenarios.
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November 2008
Cryptographic techniques (authentication, integrity, and Cryptographic techniques (authentication, integrity, and
encryption) do not protect against some types of denial of service encryption) do not protect against some types of denial of service
attacks, specifically resource exhaustion attacks based on CPU or attacks, specifically resource exhaustion attacks based on CPU or
bandwidth exhaustion. In fact, the processing required to decrypt bandwidth exhaustion. In fact, the processing required to decrypt
or check authentication may, in the case of software-based or check authentication may, in the case of software-based
cryptographic processing, in some cases increase the effect of cryptographic processing, in some cases increase the effect of
these resource exhaustion attacks. With a hardware cryptographic these resource exhaustion attacks. With a hardware cryptographic
accelerator, attack packets can be dropped at line speed without a accelerator, attack packets can be dropped at line speed without a
cost of software cycles. Cryptographic techniques may, however, be cost of software cycles. Cryptographic techniques may, however, be
useful against resource exhaustion attacks based on exhaustion of useful against resource exhaustion attacks based on exhaustion of
state information (e.g., TCP SYN attacks). state information (e.g., TCP SYN attacks).
The MPLS data plane, as presently defined, is not amenable to The MPLS data plane, as presently defined, is not amenable to
source authentication as there are no source identifiers in the source authentication as there are no source identifiers in the
MPLS packet to authenticate. The MPLS label is only locally MPLS packet to authenticate. The MPLS label is only locally
meaningful. It may be assigned by a downstream node or upstream meaningful. It may be assigned by a downstream node or upstream
node for multicast support. node for multicast support.
MPLS/GMPLS Security framework
When the MPLS payload carries identifiers that may be authenticated When the MPLS payload carries identifiers that may be authenticated
(e.g., IP packets), authentication may be carried out at the client (e.g., IP packets), authentication may be carried out at the client
level, but this does not help the MPLS SP, as these client level, but this does not help the MPLS SP, as these client
identifiers belong to an external, untrusted network. identifiers belong to an external, untrusted network.
5.1.1. Management System Authentication 5.1.1. Management System Authentication
Management system authentication includes the authentication of a Management system authentication includes the authentication of a
PE to a centrally-managed network management or directory server PE to a centrally-managed network management or directory server
when directory-based "auto-discovery" is used. It also includes when directory-based "auto-discovery" is used. It also includes
authentication of a CE to the configuration server, when a authentication of a CE to the configuration server, when a
configuration server system is used. configuration server system is used.
Authentication should be bi-directional, including PE or CE to
configuration server authentication for PE or CE to be certain it
is communicating with the right server.
5.1.2. Peer-to-Peer Authentication 5.1.2. Peer-to-Peer Authentication
Peer-to-peer authentication includes peer authentication for Peer-to-peer authentication includes peer authentication for
network control protocols (e.g., LDP, BGP, etc.), and other peer network control protocols (e.g., LDP, BGP, etc.), and other peer
authentication (i.e., authentication of one IPsec security gateway authentication (i.e., authentication of one IPsec security gateway
by another). by another).
Authentication should be bi-directional, including PE or CE to Authentication should be bi-directional, including PE or CE to
configuration server authentication for PE or CE to be certain it configuration server authentication for PE or CE to be certain it
is communicating with the right server. is communicating with the right server.
MPLS/GMPLS Security framework As indicated in Section 5.1.1, authentication should be bi-
November 2008 directional.
5.1.3. Cryptographic techniques for authenticating identity 5.1.3. Cryptographic Techniques for Authenticating Identity
Cryptographic techniques offer several mechanisms for Cryptographic techniques offer several mechanisms for
authenticating the identity of devices or individuals. These authenticating the identity of devices or individuals. These
include the use of shared secret keys, one-time keys generated by include the use of shared secret keys, one-time keys generated by
accessory devices or software, user-ID and password pairs, and a accessory devices or software, user-ID and password pairs, and a
range of public-private key systems. Another approach is to use a range of public-private key systems. Another approach is to use a
hierarchical Certification Authority system to provide digital hierarchical Certification Authority system to provide digital
certificates. certificates.
MPLS/GMPLS Security framework
This section describes or provides references to the specific This section describes or provides references to the specific
cryptographic approaches for authenticating identity. These cryptographic approaches for authenticating identity. These
approaches provide secure mechanisms for most of the authentication approaches provide secure mechanisms for most of the authentication
scenarios required in securing a MPLS/GMPLS network. scenarios required in securing a MPLS/GMPLS network.
5.2. Cryptographic Techniques 5.2. Cryptographic Techniques
MPLS/GMPLS defenses against a wide variety of attacks can be MPLS/GMPLS defenses against a wide variety of attacks can be
enhanced by the proper application of cryptographic techniques. enhanced by the proper application of cryptographic techniques.
These are the same cryptographic techniques that are applicable to These are the same cryptographic techniques that are applicable to
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configuring encryption services on devices adds to the complexity configuring encryption services on devices adds to the complexity
of their configuration and adds labor cost. Some key management of their configuration and adds labor cost. Some key management
system is usually needed. Packet sizes are typically increased when system is usually needed. Packet sizes are typically increased when
the packets are encrypted or have integrity checks or replay the packets are encrypted or have integrity checks or replay
counters added, increasing the network traffic load and adding to counters added, increasing the network traffic load and adding to
the likelihood of packet fragmentation with its increased overhead. the likelihood of packet fragmentation with its increased overhead.
(This packet length increase can often be mitigated to some extent (This packet length increase can often be mitigated to some extent
by data compression techniques, but at the expense of additional by data compression techniques, but at the expense of additional
computational burden.) Finally, some providers may employ enough computational burden.) Finally, some providers may employ enough
other defensive techniques, such as physical isolation or filtering other defensive techniques, such as physical isolation or filtering
MPLS/GMPLS Security framework
November 2008
and firewall techniques, that they may not perceive additional and firewall techniques, that they may not perceive additional
benefit from encryption techniques. benefit from encryption techniques.
Users may wish to provide confidentiality end to end. Generally, Users may wish to provide confidentiality end to end. Generally,
encrypting for confidentiality must be accompanied with encrypting for confidentiality must be accompanied with
cryptographic integrity checks to prevent certain active attacks cryptographic integrity checks to prevent certain active attacks
against the encrypted communications. On today's processors, against the encrypted communications. On today's processors,
encryption and integrity checks run extremely quickly, but key encryption and integrity checks run extremely quickly, but key
management may be more demanding in terms of both computational and management may be more demanding in terms of both computational and
administrative overhead. administrative overhead.
MPLS/GMPLS Security framework
The trust model among the MPLS/GMPLS user, the MPLS/GMPLS provider, The trust model among the MPLS/GMPLS user, the MPLS/GMPLS provider,
and other parts of the network is a major element in determining and other parts of the network is a major element in determining
the applicability of cryptographic protection for any specific the applicability of cryptographic protection for any specific
MPLS/GMPLS implementation. In particular, it determines where MPLS/GMPLS implementation. In particular, it determines where
cryptographic protection should be applied: cryptographic protection should be applied:
- If the data path between the user's site and the - If the data path between the user's site and the
provider's PE is not trusted, then it may be used on the provider's PE is not trusted, then it may be used on the
PE-CE link. PE-CE link.
- If some part of the backbone network is not trusted, - If some part of the backbone network is not trusted,
particularly in implementations where traffic may travel particularly in implementations where traffic may travel
across the Internet or multiple providers' networks, then across the Internet or multiple providers' networks, then
the PE-PE traffic may be cryptographically protected. One the PE-PE traffic may be cryptographically protected. One
also should consider cases where L1 technology may be also should consider cases where L1 technology may be
vulnerable to eavesdropping. vulnerable to eavesdropping.
- If the user does not trust any zone outside of its - If the user does not trust any zone outside of its
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access control services for the remote users. These access access control services for the remote users. These access
control services are usually protected cryptographically, control services are usually protected cryptographically,
as well. as well.
Access control usually starts with authentication of the Access control usually starts with authentication of the
entity. If cryptographic services are part of the scenario, entity. If cryptographic services are part of the scenario,
then it is important to bind the authentication to the key then it is important to bind the authentication to the key
management. Otherwise the protocol is vulnerable to being management. Otherwise the protocol is vulnerable to being
hijacked between the authentication and key management. hijacked between the authentication and key management.
MPLS/GMPLS Security framework
November 2008
Although CE-CE cryptographic protection can provide integrity and Although CE-CE cryptographic protection can provide integrity and
confidentiality against third parties, if the MPLS/GMPLS provider confidentiality against third parties, if the MPLS/GMPLS provider
has complete management control over the CE (encryption) devices, has complete management control over the CE (encryption) devices,
then it may be possible for the provider to gain access to the then it may be possible for the provider to gain access to the
user's traffic or internal network. Encryption devices could user's traffic or internal network. Encryption devices could
potentially be reconfigured to use null encryption, bypass potentially be reconfigured to use null encryption, bypass
cryptographic processing altogether, reveal internal configuration, cryptographic processing altogether, reveal internal configuration,
or provide some means of sniffing or diverting unencrypted traffic. or provide some means of sniffing or diverting unencrypted traffic.
Thus an implementation using CE-CE encryption needs to consider the Thus an implementation using CE-CE encryption needs to consider the
trust relationship between the MPLS/GMPLS user and provider. trust relationship between the MPLS/GMPLS user and provider.
MPLS/GMPLS users and providers may wish to negotiate a service MPLS/GMPLS users and providers may wish to negotiate a service
MPLS/GMPLS Security framework
level agreement (SLA) for CE-CE encryption that provides an level agreement (SLA) for CE-CE encryption that provides an
acceptable demarcation of responsibilities for management of acceptable demarcation of responsibilities for management of
cryptographic protection on the CE devices. The demarcation may cryptographic protection on the CE devices. The demarcation may
also be affected by the capabilities of the CE devices. For also be affected by the capabilities of the CE devices. For
example, the CE might support some partitioning of management, a example, the CE might support some partitioning of management, a
configuration lock-down ability, or shared capability to verify the configuration lock-down ability, or shared capability to verify the
configuration. In general, the MPLS/GMPLS user needs to have a configuration. In general, the MPLS/GMPLS user needs to have a
fairly high level of trust that the MPLS/GMPLS provider will fairly high level of trust that the MPLS/GMPLS provider will
properly provision and manage the CE devices, if the managed CE-CE properly provision and manage the CE devices, if the managed CE-CE
model is used. model is used.
5.2.1. IPsec in MPLS/GMPLS 5.2.1. IPsec in MPLS/GMPLS
IPsec [RFC4301] [RFC4302] [RFC4835] [RFC4306] [RFC2411] is the IPsec [RFC4301] [RFC4302] [RFC4835] [RFC4306] [RFC4309] [RFC2411]
security protocol of choice for encryption at the IP layer. IPsec is the security protocol of choice for encryption at the IP layer.
provides robust security for IP traffic between pairs of devices. IPsec provides robust security for IP traffic between pairs of
Non-IP traffic such as IS-IS routing must be converted to IP (e.g., devices. Non-IP traffic such as IS-IS routing must be converted to
by encapsulation) in order to use IPsec. IP (e.g., by encapsulation) in order to use IPsec.
In the MPLS/GMPLS model, IPsec can be employed to protect IP In the MPLS/GMPLS model, IPsec can be employed to protect IP
traffic between PEs, between a PE and a CE, or from CE to CE. CE- traffic between PEs, between a PE and a CE, or from CE to CE. CE-
to-CE IPsec may be employed in either a provider-provisioned or a to-CE IPsec may be employed in either a provider-provisioned or a
user-provisioned model. Likewise, IPsec protection of data user-provisioned model. Likewise, IPsec protection of data
performed within the user's site is outside the scope of this performed within the user's site is outside the scope of this
document, because it is simply handled as user data by the document, because it is simply handled as user data by the
MPLS/GMPLS core. However, if the SP performs compression, pre- MPLS/GMPLS core. However, if the SP performs compression, pre-
encryption will have a major effect on that operation. encryption will have a major effect on that operation.
IPsec does not itself specify an encryption algorithm. It can use IPsec does not itself specify an encryption algorithm. It can use
a variety of integrity or confidentiality algorithms (or even a variety of integrity or confidentiality algorithms (or even
combined integrity and confidentiality algorithms), with various combined integrity and confidentiality algorithms), with various
key lengths, such as AES encryption or AES message integrity key lengths, such as AES encryption or AES message integrity
checks. There are trade-offs between key length, computational checks. There are trade-offs between key length, computational
burden, and the level of security of the encryption. A full burden, and the level of security of the encryption. A full
MPLS/GMPLS Security framework
November 2008
discussion of these trade-offs is beyond the scope of this discussion of these trade-offs is beyond the scope of this
document. In practice, any currently recommended IPsec protection document. In practice, any currently recommended IPsec protection
offers enough security to reduce the likelihood of its being offers enough security to reduce the likelihood of its being
directly targeted by an attacker substantially; other weaker links directly targeted by an attacker substantially; other weaker links
in the chain of security are likely to be attacked first. in the chain of security are likely to be attacked first.
MPLS/GMPLS users may wish to use a Service Level Agreement (SLA) MPLS/GMPLS users may wish to use a Service Level Agreement (SLA)
specifying the SP's responsibility for ensuring data integrity and specifying the SP's responsibility for ensuring data integrity and
confidentiality, rather than analyzing the specific encryption confidentiality, rather than analyzing the specific encryption
techniques used in the MPLS/GMPLS service. techniques used in the MPLS/GMPLS service.
Encryption algorithms generally come with two parameters: mode such Encryption algorithms generally come with two parameters: mode such
as Cipher Block Chaining and key length such as AES-192. (This as Cipher Block Chaining and key length such as AES-192. (This
should not be confused with two other senses in which the word should not be confused with two other senses in which the word
MPLS/GMPLS Security framework
"mode" is used: IPsec itself can be used in Tunnel Mode or "mode" is used: IPsec itself can be used in Tunnel Mode or
Transport Mode, and IKE [version 1] uses Main Mode, Aggressive Transport Mode, and IKE [version 1] uses Main Mode, Aggressive
Mode, or Quick Mode). It should be stressed that IPsec encryption Mode, or Quick Mode). It should be stressed that IPsec encryption
without an integrity check is a state of sin. without an integrity check is a state of sin.
For many of the MPLS/GMPLS provider's network control messages and For many of the MPLS/GMPLS provider's network control messages and
some user requirements, cryptographic authentication of messages some user requirements, cryptographic authentication of messages
without encryption of the contents of the message may provide without encryption of the contents of the message may provide
appropriate security. Using IPsec, authentication of messages is appropriate security. Using IPsec, authentication of messages is
provided by the Authentication Header (AH) or through the use of provided by the Authentication Header (AH) or through the use of
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Algorithm 1 (SHA-1) [RFC3174]. No attacks against HMAC SHA-1 are Algorithm 1 (SHA-1) [RFC3174]. No attacks against HMAC SHA-1 are
likely to play out in the near future, but it is possible that likely to play out in the near future, but it is possible that
people will soon find SHA-1 collisions. Thus, it is important that people will soon find SHA-1 collisions. Thus, it is important that
mechanisms be designed to be flexible about the choice of hash mechanisms be designed to be flexible about the choice of hash
functions and message integrity checks. Also, many of these functions and message integrity checks. Also, many of these
mechanisms do not include a convenient way to manage and update mechanisms do not include a convenient way to manage and update
keys. keys.
A mechanism to provide a combination of confidentiality, data A mechanism to provide a combination of confidentiality, data
origin authentication, and connectionless integrity is the use of origin authentication, and connectionless integrity is the use of
AES in CCM (Counter with CBC-MAC) mode (RFC 4309) [RFC4309], with AES in GCM (Counter with CBC-MAC) mode (RFC 4106) [RFC4106].
an explicit initialization vector (IV), as the IPsec ESP. Recently,
GCM is rapidly replacing CCM as the preferred method: [RFC4103].
5.2.2. MPLS / GMPLS DiffServ and IPsec 5.2.2. MPLS / GMPLS DiffServ and IPsec
MPLS and GMPLS, which provide differentiated services based on MPLS and GMPLS, which provide differentiated services based on
traffic type, may encounter some conflicts with IPsec encryption of traffic type, may encounter some conflicts with IPsec encryption of
traffic. Because encryption hides the content of the packets, it traffic. Because encryption hides the content of the packets, it
MPLS/GMPLS Security framework
November 2008
may not be possible to differentiate the encrypted traffic in the may not be possible to differentiate the encrypted traffic in the
same manner as unencrypted traffic. Although DiffServ markings are same manner as unencrypted traffic. Although DiffServ markings are
copied to the IPsec header and can provide some differentiation, copied to the IPsec header and can provide some differentiation,
not all traffic types can be accommodated by this mechanism. Using not all traffic types can be accommodated by this mechanism. Using
IPsec without IKE or IKEv2 (the better choice) is not advisable. IPsec without IKE or IKEv2 (the better choice) is not advisable.
IKEv2 provides IPsec Security Association creation and management, IKEv2 provides IPsec Security Association creation and management,
entity authentication, key agreement, and key update. It works with entity authentication, key agreement, and key update. It works with
a variety of authentication methods including pre-shared keys, a variety of authentication methods including pre-shared keys,
public key certificates, and EAP. If DoS attacks against IKEv2 are public key certificates, and EAP. If DoS attacks against IKEv2 are
considered an important threat to mitigate, the cookie-based anti- considered an important threat to mitigate, the cookie-based anti-
spoofing feature of IKEv2 should be used. IKEv2 has its own set of spoofing feature of IKEv2 should be used. IKEv2 has its own set of
cryptographic methods, but any of the default suites specified in cryptographic methods, but any of the default suites specified in
[RFC4308] or [RFC4869] provides more than adequate security. [RFC4308] or [RFC4869] provides more than adequate security.
5.2.3. Encryption for device configuration and management MPLS/GMPLS Security framework
5.2.3. Encryption for Device Configuration and Management
For configuration and management of MPLS/GMPLS devices, encryption For configuration and management of MPLS/GMPLS devices, encryption
and authentication of the management connection at a level and authentication of the management connection at a level
comparable to that provided by IPsec is desirable. comparable to that provided by IPsec is desirable.
Several methods of transporting MPLS/GMPLS device management Several methods of transporting MPLS/GMPLS device management
traffic offer security and confidentiality. traffic offer authentication, integrity, and confidentiality.
- Secure Shell (SSH) offers protection for TELNET [STD-8] or - Secure Shell (SSH) offers protection for TELNET [STD-8] or
terminal-like connections to allow device configuration. terminal-like connections to allow device configuration.
- SNMPv3 [STD62] provides encrypted and authenticated protection - SNMPv3 [STD62] provides encrypted and authenticated protection
for SNMP-managed devices. for SNMP-managed devices.
- Transport Layer Security (TLS) [RFC5246] and the closely-related - Transport Layer Security (TLS) [RFC5246] and the closely-related
Secure Sockets Layer (SSL) are widely used for securing HTTP- Secure Sockets Layer (SSL) are widely used for securing HTTP-
based communication, and thus can provide support for most XML- based communication, and thus can provide support for most XML-
and SOAP-based device management approaches. and SOAP-based device management approaches.
- Since 2004, there has been extensive work proceeding in several - Since 2004, there has been extensive work proceeding in several
organizations (OASIS, W3C, WS-I, and others) on securing device organizations (OASIS, W3C, WS-I, and others) on securing device
management traffic within a "Web Services" framework, using a management traffic within a "Web Services" framework, using a
wide variety of security models, and providing support for wide variety of security models, and providing support for
multiple security token formats, multiple trust domains, multiple security token formats, multiple trust domains,
multiple signature formats, and multiple encryption multiple signature formats, and multiple encryption
technologies. technologies.
- IPsec provides the services with integrity and confidentiality - IPsec provides security services including integrity and
at the network layer. With regards to device management, its confidentiality at the network layer. With regards to device
current use is primarily focused on in-band management of user- management, its current use is primarily focused on in-band
managed IPsec gateway devices. management of user-managed IPsec gateway devices.
- There are recent work in ISMS WG (Integrated Security Model for - There are recent work in the ISMS WG (Integrated Security Model
SNMP Working Group) to define how to use SSH to secure SNMP, due for SNMP Working Group) to define how to use SSH to secure SNMP,
to the limited deployment of SNMPv3; and the possibility of due to the limited deployment of SNMPv3; and the possibility of
using Kerberos, particularly for interfaces like TELNET, where using Kerberos, particularly for interfaces like TELNET, where
client code exists. client code exists.
MPLS/GMPLS Security framework
November 2008
5.2.4. Security Considerations for MPLS Pseudowires 5.2.4. Security Considerations for MPLS Pseudowires
In addition to IP traffic, MPLS networks may be used to transport In addition to IP traffic, MPLS networks may be used to transport
other services such as Ethernet, ATM, Frame Relay, and TDM. This is other services such as Ethernet, ATM, Frame Relay, and TDM. This is
done by setting up pseudowires (PWs) that tunnel the native service done by setting up pseudowires (PWs) that tunnel the native service
through the MPLS core by encapsulating at the edges. The PWE through the MPLS core by encapsulating at the edges. The PWE
architecture is defined in [RFC3985]. architecture is defined in [RFC3985].
PW tunnels may be set up using the PWE control protocol based on PW tunnels may be set up using the PWE control protocol based on
LDP [RFC4447], and thus security considerations for LDP will most LDP [RFC4447], and thus security considerations for LDP will most
likely be applicable to the PWE3 control protocol as well. likely be applicable to the PWE3 control protocol as well.
MPLS/GMPLS Security framework
PW user packets contain at least one MPLS label (the PW label) and PW user packets contain at least one MPLS label (the PW label) and
may contain one or more MPLS tunnel labels. After the label stack may contain one or more MPLS tunnel labels. After the label stack,
there is a four-byte control word (which is optional for some PW there is a four-byte control word (which is optional for some PW
types), followed by the native service payload. It must be types), followed by the native service payload. It must be
stressed that encapsulation of MPLS PW packets in IP for the stressed that encapsulation of MPLS PW packets in IP for the
purpose of enabling use of IPsec mechanisms is not a valid option. purpose of enabling use of IPsec mechanisms is not a valid option.
The PW client traffic may be secured by use of mechanisms beyond The PW client traffic may be secured by use of mechanisms beyond
the scope of this document. the scope of this document.
5.2.5. End-to-End versus Hop-by-Hop Protection Tradeoffs 5.2.5. End-to-End versus Hop-by-Hop Protection Tradeoffs
in MPLS/GMPLS in MPLS/GMPLS
skipping to change at page 25, line 5 skipping to change at page 25, line 36
protect the traffic passing between them. The devices may be protect the traffic passing between them. The devices may be
directly connected (over a single "hop"), or intervening devices directly connected (over a single "hop"), or intervening devices
may transport the protected traffic between the pair of devices. may transport the protected traffic between the pair of devices.
The extreme cases involve using protection between every adjacent The extreme cases involve using protection between every adjacent
pair of devices along a given path (hop-by-hop), or using pair of devices along a given path (hop-by-hop), or using
protection only between the end devices along a given path (end-to- protection only between the end devices along a given path (end-to-
end). To keep this discussion within the scope of this document, end). To keep this discussion within the scope of this document,
the latter ("end-to-end") case considered here is CE-to-CE rather the latter ("end-to-end") case considered here is CE-to-CE rather
than fully end-to-end. than fully end-to-end.
MPLS/GMPLS Security framework
November 2008
Figure 3 depicts a simplified topology showing the Customer Edge Figure 3 depicts a simplified topology showing the Customer Edge
(CE) devices, the Provider Edge (PE) devices, and a variable number (CE) devices, the Provider Edge (PE) devices, and a variable number
(three are shown) of Provider core (P) devices, which might be (three are shown) of Provider core (P) devices, which might be
present along the path between two sites in a single VPN operated present along the path between two sites in a single VPN operated
by a single service provider (SP). by a single service provider (SP).
Site_1---CE---PE---P---P---P---PE---CE---Site_2 Site_1---CE---PE---P---P---P---PE---CE---Site_2
Figure 3: Simplified topology traversing through MPLS/GMPLS core. Figure 3: Simplified topology traversing through MPLS/GMPLS core.
Within this simplified topology, and assuming that the P devices Within this simplified topology, and assuming that the P devices
are not involved with cryptographic protection, four basic, are not involved with cryptographic protection, four basic,
MPLS/GMPLS Security framework
feasible configurations exist for protecting connections among the feasible configurations exist for protecting connections among the
devices: devices:
1) Site-to-site (CE-to-CE) - Apply confidentiality or integrity 1) Site-to-site (CE-to-CE) - Apply confidentiality or integrity
services between the two CE devices, so that traffic will be services between the two CE devices, so that traffic will be
protected throughout the SP's network. protected throughout the SP's network.
2) Provider edge-to-edge (PE-to-PE) - Apply confidentiality or 2) Provider edge-to-edge (PE-to-PE) - Apply confidentiality or
integrity services between the two PE devices. Unprotected traffic integrity services between the two PE devices. Unprotected
is received at one PE from the customer's CE, then it is protected traffic is received at one PE from the customer's CE, then it is
for transmission through the SP's network to the other PE, and protected for transmission through the SP's network to the other
finally it is decrypted or checked for integrity and sent to the PE, and finally it is decrypted or checked for integrity and
other CE. sent to the other CE.
3) Access link (CE-to-PE) - Apply confidentiality or integrity 3) Access link (CE-to-PE) - Apply confidentiality or integrity
services between the CE and PE on each side or on only one side. services between the CE and PE on each side or on only one side.
4) Configurations 2 and 3 above can also be combined, with 4) Configurations 2 and 3 above can also be combined, with
confidentiality or integrity running from CE to PE, then PE to PE, confidentiality or integrity running from CE to PE, then PE to
and then PE to CE. PE, and then PE to CE.
Among the four feasible configurations, key tradeoffs in Among the four feasible configurations, key tradeoffs in
considering encryption include: considering encryption include:
- Vulnerability to link eavesdropping or tampering - assuming an - Vulnerability to link eavesdropping or tampering - assuming an
attacker can attacker can observe or modify data in transit on the links,
observe or modify data in transit on the links, would it be would it be protected by encryption?
protected by encryption?
- Vulnerability to device compromise - assuming an attacker can get - Vulnerability to device compromise - assuming an attacker can get
access to a device (or freely alter its configuration), would the access to a device (or freely alter its configuration), would the
data be protected? data be protected?
MPLS/GMPLS Security framework
November 2008
- Complexity of device configuration and management - given the - Complexity of device configuration and management - given the
number of sites per VPN customer as Nce and the number of PEs number of sites per VPN customer as Nce and the number of PEs
participating in a given VPN as Npe, how many device configurations participating in a given VPN as Npe, how many device
need to be created or maintained, and how do those configurations configurations need to be created or maintained, and how do those
scale? configurations scale?
- Processing load on devices - how many cryptographic operations - Processing load on devices - how many cryptographic operations
must be performed given N packets? - This raises considerations of must be performed given N packets? - This raises considerations
device capacity and perhaps end-to-end delay. of device capacity and perhaps end-to-end delay.
- Ability of the SP to provide enhanced services (QoS, firewall, - Ability of the SP to provide enhanced services (QoS, firewall,
intrusion detection, etc.) - Can the SP inspect the data to provide intrusion detection, etc.) - Can the SP inspect the data to
these services? provide these services?
These tradeoffs are discussed for each configuration, below: These tradeoffs are discussed for each configuration, below:
MPLS/GMPLS Security framework
1) Site-to-site (CE-to-CE) 1) Site-to-site (CE-to-CE)
Link eavesdropping or tampering - protected on all links Link eavesdropping or tampering - protected on all links.
Device compromise - vulnerable to CE compromise Device compromise - vulnerable to CE compromise.
Complexity - single administration, responsible for one device per Complexity - single administration, responsible for one device per
site (Nce devices), but overall configuration per VPN scales as site (Nce devices), but overall configuration per VPN scales as
Nce**2. Nce**2.
Though the complexity may be reduced: 1) In practice, as Nce Though the complexity may be reduced: 1) In practice, as Nce
grows, the number of VPNs falls off from being a full clique; grows, the number of VPNs falls off from being a full clique;
2) If the CEs run an automated key management protocol, then 2) If the CEs run an automated key management protocol, then
they should be able to set up and tear down secured VPNs they should be able to set up and tear down secured VPNs
without any intervention without any intervention.
Processing load - on each of two CEs, each packet is either
Processing load - on each of two CEs, each packet is
cryptographically processed (2P), though the protection may be cryptographically processed (2P), though the protection may be
"integrity check only" or "integrity check plus encryption." "integrity check only" or "integrity check plus encryption."
Enhanced services - severely limited; typically only Diffserv Enhanced services - severely limited; typically only Diffserv
markings are visible to the SP, allowing some QoS services markings are visible to the SP, allowing some QoS services. The
CEs could also use the IPv6 Flow Label to identify traffic
classes.
2) Provider edge-to-edge (PE-to-PE) 2) Provider Edge-to-Edge (PE-to-PE)
Link eavesdropping or tampering - vulnerable on CE-PE links; Link eavesdropping or tampering - vulnerable on CE-PE links;
protected on SP's network links protected on SP's network links.
Device compromise - vulnerable to CE or PE compromise
Device compromise - vulnerable to CE or PE compromise.
Complexity - single administration, Npe devices to configure. Complexity - single administration, Npe devices to configure.
(Multiple sites may share a PE device so Npe is typically much (Multiple sites may share a PE device so Npe is typically much
less than Nce.) Scalability of the overall configuration smaller than Nce.) Scalability of the overall configuration
depends on the PPVPN type: If the cryptographic protection is depends on the PPVPN type: If the cryptographic protection is
separate per VPN context, it scales as Npe**2 per customer VPN. separate per VPN context, it scales as Npe**2 per customer VPN.
If it is per-PE, it scales as Npe**2 for all customer VPNs If it is per-PE, it scales as Npe**2 for all customer VPNs
combined. combined.
Processing load - on each of two PEs, each packet is Processing load - on each of two PEs, each packet is
cryptographically processed (2P). Note that this 2P is a cryptographically processed (2P).
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different 2P from case (1), because only PEs are in
consideration here.
Enhanced services - full; SP can apply any enhancements based on Enhanced services - full; SP can apply any enhancements based on
detailed view of traffic detailed view of traffic.
3) Access link (CE-to-PE) 3) Access Link (CE-to-PE)
Link eavesdropping or tampering - protected on CE-PE link; Link eavesdropping or tampering - protected on CE-PE link;
vulnerable on SP's network links vulnerable on SP's network links
MPLS/GMPLS Security framework
Device compromise - vulnerable to CE or PE compromise Device compromise - vulnerable to CE or PE compromise
Complexity - two administrations (customer and SP) with device Complexity - two administrations (customer and SP) with device
configuration on each side (Nce + Npe devices to configure) but configuration on each side (Nce + Npe devices to configure) but
because there is no mesh the overall configuration scales as because there is no mesh the overall configuration scales as
Nce. Nce.
Processing load - on each of two CEs, each packet is Processing load - on each of two CEs, each packet is
cryptographically processed, plus on each of two PEs, each cryptographically processed, plus on each of two PEs, each
packet is cryptographically processed (4P) packet is cryptographically processed (4P)
Enhanced services - full; SP can apply any enhancements based on Enhanced services - full; SP can apply any enhancements based on
detailed view of traffic detailed view of traffic
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Scalability of the overall configuration depends on the PPVPN Scalability of the overall configuration depends on the PPVPN
type: If the cryptographic processing is separate per VPN type: If the cryptographic processing is separate per VPN
context, it scales as Npe**2 per customer VPN. If it is per- context, it scales as Npe**2 per customer VPN. If it is per-
PE, it scales as Npe**2 for all customer VPNs combined. PE, it scales as Npe**2 for all customer VPNs combined.
Processing load - on each of two CEs, each packet is Processing load - on each of two CEs, each packet is
cryptographically processed, plus on each of two PEs, each cryptographically processed, plus on each of two PEs, each
packet is cryptographically processed twice (6P) packet is cryptographically processed twice (6P)
Enhanced services - full; SP can apply any enhancements based on Enhanced services - full; SP can apply any enhancements based on
detailed view of traffic detailed view of traffic
Given the tradeoffs discussed above, a few conclusions can be made: Given the tradeoffs discussed above, a few conclusions can be
drawn:
- Configurations 2 and 3 are subsets of 4 that may be appropriate - Configurations 2 and 3 are subsets of 4 that may be appropriate
alternatives to 4 under certain threat models; the remainder of alternatives to 4 under certain threat models; the remainder of
these conclusions compare 1 (CE-to-CE) versus 4 (combined access these conclusions compare 1 (CE-to-CE) versus 4 (combined access
links and PE-to-PE). links and PE-to-PE).
- If protection from link eavesdropping or tampering is all that is - If protection from link eavesdropping or tampering is all that is
important, then configurations 1 and 4 are equivalent. important, then configurations 1 and 4 are equivalent.
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November 2008
- If protection from device compromise is most important and the - If protection from device compromise is most important and the
threat is to the CE devices, both cases are equivalent; if the threat is to the CE devices, both cases are equivalent; if the
threat is to the PE devices, configuration 1 is better. threat is to the PE devices, configuration 1 is better.
- If reducing complexity is most important, and the size of the - If reducing complexity is most important, and the size of the
network is small, configuration 1 is better. Otherwise network is small, configuration 1 is better. Otherwise
configuration 4 is better because rather than a mesh of CE devices configuration 4 is better because rather than a mesh of CE
it requires a smaller mesh of PE devices. Also, under some PPVPN devices it requires a smaller mesh of PE devices. Also, under
approaches the scaling of 4 is further improved by sharing the same some PPVPN approaches the scaling of 4 is further improved by
PE-PE mesh across all VPN contexts. The scaling advantage of 4 may sharing the same PE-PE mesh across all VPN contexts. The scaling
be increased or decreased in any given situation if the CE devices MPLS/GMPLS Security framework
are simpler to configure than the PE devices, or vice-versa. advantage of 4 may be increased or decreased in any given
situation if the CE devices are simpler to configure than the PE
devices, or vice-versa.
- If the overall processing load is a key factor, then 1 is better, - If the overall processing load is a key factor, then 1 is
unless the PEs come with a hardware encryption accelerator and the better, unless the PEs come with a hardware encryption
CEs do not. accelerator and the CEs do not.
- If the availability of enhanced services support from the SP is - If the availability of enhanced services support from the
most important, then 4 is best. SP is most important, then 4 is best.
- If users are concerned with having their VPNs misconnected
with other users' VPNs, then encrpytion with 1 can provide
protection.
As a quick overall conclusion, CE-to-CE protection is better As a quick overall conclusion, CE-to-CE protection is better
against device compromise, but this comes at the cost of enhanced against device compromise, but this comes at the cost of enhanced
services and at the cost of operational complexity due to the services and at the cost of operational complexity due to the
Order(n**2) scaling of a larger mesh. Order(n**2) scaling of a larger mesh.
This analysis of site-to-site vs. hop-by-hop tradeoffs does not This analysis of site-to-site vs. hop-by-hop tradeoffs does not
explicitly include cases of multiple providers cooperating to explicitly include cases of multiple providers cooperating to
provide a PPVPN service, public Internet VPN connectivity, or provide a PPVPN service, public Internet VPN connectivity, or
remote access VPN service, but many of the tradeoffs will be remote access VPN service, but many of the tradeoffs are similar.
similar.
In addition to the simplified models, the following should also be In addition to the simplified models, the following should also be
considered: considered:
- There are reasons, perhaps, to protect a specific P-to-P or PE- - There are reasons, perhaps, to protect a specific P-to-P or PE-
to-P. to-P.
- There may be reasons to do multiple encryptions over certain - There may be reasons to do multiple encryptions over certain
segments. One may be using an encrypted wireless link under our segments. One may be using an encrypted wireless link under our
IPsec VPN to access a SSL-secured web site to download encrypted IPsec VPN to access a SSL-secured web site to download encrypted
email attachments: four layers.) email attachments: four layers.)
- It may be that, for example, cryptographic integrity checks are - It may be appropriate that, for example, cryptographic integrity
applied end to end, and confidentiality over a shorter span. checks are applied end to end, and confidentiality over a shorter
span.
- Different cryptographic protection may be required for control - Different cryptographic protection may be required for control
protocols and data traffic. protocols and data traffic.
- Attention needs to be given to how auxiliary traffic is - Attention needs to be given to how auxiliary traffic is
protected, e.g., the ICMPv6 packets that flow back during PMTU protected, e.g., the ICMPv6 packets that flow back during PMTU
discovery, among other examples. discovery, among other examples.
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5.3. Access Control Techniques 5.3. Access Control Techniques
Access control techniques include packet-by-packet or packet-flow- Access control techniques include packet-by-packet or packet-flow-
by-packet-flow access control by means of filters and firewalls on by-packet-flow access control by means of filters and firewalls on
IPv4/IPv6 packets, as well as by means of admitting a "session" for IPv4/IPv6 packets, as well as by means of admitting a "session" for
a control, signaling, or management protocol. Enforcement of access a control, signaling, or management protocol. Enforcement of access
MPLS/GMPLS Security framework
control by isolated infrastructure addresses is discussed in control by isolated infrastructure addresses is discussed in
another section of this document. section 5.4 of this document.
In this document, we distinguish between filtering and firewalls In this document, we distinguish between filtering and firewalls
based primarily on the direction of traffic flow. We define based primarily on the direction of traffic flow. We define
filtering as being applicable to unidirectional traffic, while a filtering as being applicable to unidirectional traffic, while a
firewall can analyze and control both sides of a conversation. firewall can analyze and control both sides of a conversation.
The definition has two significant corollaries: The definition has two significant corollaries:
- Routing or traffic flow symmetry: A firewall typically requires - Routing or traffic flow symmetry: A firewall typically requires
routing symmetry, which is usually enforced by locating a firewall routing symmetry, which is usually enforced by locating a firewall
where the network topology assures that both sides of a where the network topology assures that both sides of a
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- Statefulness: Because it receives both sides of a conversation, a - Statefulness: Because it receives both sides of a conversation, a
firewall may be able to interpret a significant amount of firewall may be able to interpret a significant amount of
information concerning the state of that conversation and use this information concerning the state of that conversation and use this
information to control access. A filter can maintain some limited information to control access. A filter can maintain some limited
state information on a unidirectional flow of packets, but cannot state information on a unidirectional flow of packets, but cannot
determine the state of the bi-directional conversation as precisely determine the state of the bi-directional conversation as precisely
as a firewall. as a firewall.
5.3.1. Filtering 5.3.1. Filtering
It is relatively common for routers to filter data packets. That It is relatively common for routers to filter packets. That is,
is, routers can look for particular values in certain fields of the routers can look for particular values in certain fields of the IP
IP or higher level (e.g., TCP or UDP) headers. Packets which or higher level (e.g., TCP or UDP) headers. Packets matching the
matching the criteria associated with a particular filter may criteria associated with a particular filter may either be
either be discarded or given special treatment. Today, not only discarded or given special treatment. Today, not only routers, most
routers, most end hosts today have filters and every instance of end hosts have filters, and every instance of IPsec is also a
IPsec is also a filter [RFC4301]. filter [RFC4301].
In discussing filters, it is useful to separate the Filter In discussing filters, it is useful to separate the Filter
Characteristics that may be used to determine whether a packet Characteristics that may be used to determine whether a packet
matches a filter from the Packet Actions applied to those packets matches a filter from the Packet Actions applied to those packets
which matching a particular filter. matching a particular filter.
o Filter Characteristics o Filter Characteristics
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November 2008
Filter characteristics or rules are used to determine whether a Filter characteristics or rules are used to determine whether a
particular packet or set of packets matches a particular filter. particular packet or set of packets matches a particular filter.
In many cases filter characteristics may be stateless. A stateless In many cases filter characteristics may be stateless. A stateless
filter determines whether a particular packet matches a filter filter determines whether a particular packet matches a filter
based solely on the filter definition, normal forwarding based solely on the filter definition, normal forwarding
information (such as the next hop for a packet), and the contents information (such as the next hop for a packet), the interface on
of that individual packet. Typically stateless filters may consider MPLS/GMPLS Security framework
the incoming and outgoing logical or physical interface, which a packet arrived, and the contents of that individual packet.
information in the IP header, and information in higher layer Typically, stateless filters may consider the incoming and outgoing
headers such as the TCP or UDP header. Information in the IP header logical or physical interface, information in the IP header, and
to be considered may for example include source and destination IP information in higher layer headers such as the TCP or UDP header.
addresses, Protocol field, Fragment Offset, and TOS field in IPv4, Information in the IP header to be considered may for example
Next Header, Extension Headers, Flow label, etc. in IPv6. Filters include source and destination IP addresses; Protocol field,
also may consider fields in the TCP or UDP header such as the Port Fragment Offset, and TOS field in IPv4; or Next Header, Extension
fields, the SYN field in the TCP header, as well as ICMP and ICMPv6 Headers, Flow label, etc. in IPv6. Filters also may consider fields
type. in the TCP or UDP header such as the Port numbers, the SYN field in
the TCP header, as well as ICMP and ICMPv6 type.
Stateful filtering maintains packet-specific state information, to Stateful filtering maintains packet-specific state information to
aid in determining whether a filter has been met. For example, a aid in determining whether a filter rule has been met. For example,
device might apply stateless filters to the first fragment of a a device might apply stateless filtering to the first fragment of a
fragmented IP packet. If the filter matches, then the data unit ID fragmented IPv4 packet. If the filter matches, then the data unit
may be remembered and other fragments of the same packet may then ID may be remembered and other fragments of the same packet may
be considered to match the same filter. Stateful filtering is more then be considered to match the same filter. Stateful filtering is
commonly done in firewalls, although firewall technology may be more commonly done in firewalls, although firewall technology may
added to routers. Data unit ID can also be Fragmentation Extension be added to routers. Data unit ID can also be Fragment Extension
Header in IPv6. Header Identification field in IPv6.
o Actions based on Filter Results o Actions based on Filter Results
If a packet, or a series of packets, matches a specific filter, If a packet, or a series of packets, matches a specific filter,
then a variety of actions which may be taken based on that match. then a variety of actions which may be taken based on that match.
Examples of such actions include: Examples of such actions include:
- Discard - Discard
In many cases, filters are set to catch certain undesirable In many cases, filters are set to catch certain undesirable
packets. Examples may include packets with forged or invalid source packets. Examples may include packets with forged or invalid source
addresses, packets that are part of a DOS or Distributed DoS (DDOS) addresses, packets that are part of a DoS or Distributed DoS (DDoS)
attack, or packets which are trying to access unallowed resources attack, or packets trying to access unallowed resources (such as
(such as network management packets from an unauthorized source). network management packets from an unauthorized source). Where such
Where such filters are activated, it is common to discard the filters are activated, it is common to discard the packet or set of
packet or set of packets matching the filter silently. The packets matching the filter silently. The discarded packets may of
discarded packets may of course also be counted or logged. course also be counted or logged.
- Set CoS - Set CoS
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November 2008
A filter may be used to set the Class of Service associated with A filter may be used to set the Class of Service associated with
the packet. the packet.
- Count packets or bytes - Count packets or bytes
- Rate Limit - Rate Limit
MPLS/GMPLS Security framework
In some cases the set of packets matching a particular filter may In some cases the set of packets matching a particular filter may
be limited to a specified bandwidth. In this case, packets or bytes be limited to a specified bandwidth. In this case, packets or bytes
would be counted, and would be forwarded normally up to the would be counted, and would be forwarded normally up to the
specified limit. Excess packets may be discarded or may be marked specified limit. Excess packets may be discarded or may be marked
(for example by setting a "discard eligible" bit in the IP ToS (for example by setting a "discard eligible" bit in the IPv4 ToS
field or the MPLS EXP field). field or the MPLS EXP field).
- Forward and Copy - Forward and Copy
It is useful in some cases to forward some set of packets normally, It is useful in some cases to forward some set of packets normally,
but also to send a copy to a specified other address or interface. but also to send a copy to a specified other address or interface.
For example, this may be used to implement a lawful intercept For example, this may be used to implement a lawful intercept
capability or to feed selected packets to an Intrusion Detection capability or to feed selected packets to an Intrusion Detection
System. System.
o Other Issues related to Use of Packet Filters o Other Packet Filters Issues
Filtering performance may vary widely according to implementation Filtering performance may vary widely according to implementation
and the types and number of rules. Without acceptable performance, and the types and number of rules. Without acceptable performance,
filtering is not useful. filtering is not useful.
The precise definition of "acceptable" may vary from SP to SP, and The precise definition of "acceptable" may vary from SP to SP, and
may depend upon the intended use of the filters. For example, for may depend upon the intended use of the filters. For example, for
some uses a filter may be turned on all the time to set CoS, to some uses a filter may be turned on all the time to set CoS, to
prevent an attack, or to mitigate the effect of a possible future prevent an attack, or to mitigate the effect of a possible future
attack. In this case it is likely that the SP will want the filter attack. In this case it is likely that the SP will want the filter
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a major DDoS attack). In this case a greater performance impact may a major DDoS attack). In this case a greater performance impact may
be acceptable to some service providers. be acceptable to some service providers.
A key consideration with the use of packet filters is that they can A key consideration with the use of packet filters is that they can
provide few options for filtering packets carrying encrypted data. provide few options for filtering packets carrying encrypted data.
Because the data itself is not accessible, only packet header Because the data itself is not accessible, only packet header
information or other unencrypted fields can be used for filtering. information or other unencrypted fields can be used for filtering.
5.3.2. Firewalls 5.3.2. Firewalls
Firewalls provide a mechanism for control over traffic passing Firewalls provide a mechanism for controlling traffic passing
between different trusted zones in the MPLS/GMPLS model, or between between different trusted zones in the MPLS/GMPLS model or between
a trusted zone and an untrusted zone. Firewalls typically provide a trusted zone and an untrusted zone. Firewalls typically provide
MPLS/GMPLS Security framework
November 2008
much more functionality than filters, because they may be able to much more functionality than filters, because they may be able to
apply detailed analysis and logical functions to flows, and not apply detailed analysis and logical functions to flows, and not
just to individual packets. They may offer a variety of complex just to individual packets. They may offer a variety of complex
services, such as threshold-driven denial-of-service attack services, such as threshold-driven DoS attack protection, virus
protection, virus scanning, acting as a TCP connection proxy, etc. scanning, acting as a TCP connection proxy, etc.
MPLS/GMPLS Security framework
As with other access control techniques, the value of firewalls As with other access control techniques, the value of firewalls
depends on a clear understanding of the topologies of the depends on a clear understanding of the topologies of the
MPLS/GMPLS core network, the user networks, and the threat model. MPLS/GMPLS core network, the user networks, and the threat model.
Their effectiveness depends on a topology with a clearly defined Their effectiveness depends on a topology with a clearly defined
inside (secure) and outside (not secure). inside (secure) and outside (not secure).
Firewalls may be applied to help protect MPLS/GMPLS core network Firewalls may be applied to help protect MPLS/GMPLS core network
functions from attacks originating from the Internet or from functions from attacks originating from the Internet or from
MPLS/GMPLS user sites, but typically other defensive techniques MPLS/GMPLS user sites, but typically other defensive techniques
will be used for this purpose. will be used for this purpose.
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information, other unencrypted fields, or analysis of the flow of information, other unencrypted fields, or analysis of the flow of
encrypted packets can be used for making decisions on accepting or encrypted packets can be used for making decisions on accepting or
rejecting encrypted traffic. rejecting encrypted traffic.
Two approaches are to move the firewall outside of the encrypted Two approaches are to move the firewall outside of the encrypted
part of the path or to register and pre-approve the encrypted part of the path or to register and pre-approve the encrypted
session with the firewall. session with the firewall.
Handling DoS attacks has become increasingly important. Useful Handling DoS attacks has become increasingly important. Useful
guidelines include the following: guidelines include the following:
1. Perform ingress filtering everywhere. Upstream prevention is 1. Perform ingress filtering everywhere. Upstream detection and
better. prevention are better.
2. Be able to filter DoS attack packets at line speed. 2. Be able to filter DoS attack packets at line speed.
3. Do not allow oneself to amplify attacks. 3. Do not allow oneself to amplify attacks.
4. Continue processing legitimate traffic. Over provide for heavy 4. Continue processing legitimate traffic. Over provide for heavy
loads. Use diverse locations, technologies, etc. loads. Use diverse locations, technologies, etc.
5.3.3. Access Control to management interfaces 5.3.3. Access Control to Management Interfaces
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November 2008
Most of the security issues related to management interfaces can be Most of the security issues related to management interfaces can be
addressed through the use of authentication techniques as described addressed through the use of authentication techniques as described
in the section on authentication. However, additional security may in the section on authentication. However, additional security may
be provided by controlling access to management interfaces in other be provided by controlling access to management interfaces in other
ways. ways.
The Optical Internetworking Forum has done good work on protecting MPLS/GMPLS Security framework
such interfaces with TLS, SSH, Kerberos, IPsec, WSS, etc. See OIF- The Optical Internetworking Forum has done relevant work on
SMI-01.0 "Security for Management Interfaces to Network Elements" protecting such interfaces with TLS, SSH, Kerberos, IPsec, WSS,
[OIF-SMI-01.0], and "Addendum to the Security for Management etc. See OIF-SMI-01.0 "Security for Management Interfaces to
Interfaces to Network Elements" [OIF-SMI-02.1]. See also the work Network Elements" [OIF-SMI-01.0], and "Addendum to the Security for
in the ISMS WG. Management Interfaces to Network Elements" [OIF-SMI-02.1]. See also
the work in the ISMS WG.
Management interfaces, especially console ports on MPLS/GMPLS Management interfaces, especially console ports on MPLS/GMPLS
devices, may be configured so they are only accessible out-of-band, devices, may be configured so they are only accessible out-of-band,
through a system which is physically or logically separated from through a system which is physically or logically separated from
the rest of the MPLS/GMPLS infrastructure. the rest of the MPLS/GMPLS infrastructure.
Where management interfaces are accessible in-band within the Where management interfaces are accessible in-band within the
MPLS/GMPLS domain, filtering or firewalling techniques can be used MPLS/GMPLS domain, filtering or firewalling techniques can be used
to restrict unauthorized in-band traffic from having access to to restrict unauthorized in-band traffic from having access to
management interfaces. Depending on device capabilities, these management interfaces. Depending on device capabilities, these
filtering or firewalling techniques can be configured either on filtering or firewalling techniques can be configured either on
other devices through which the traffic might pass, or on the other devices through which the traffic might pass, or on the
individual MPLS/GMPLS devices themselves. individual MPLS/GMPLS devices themselves.
5.4. Use of Isolated Infrastructure 5.4. Use of Isolated Infrastructure
One way to protect the infrastructure used for support of One way to protect the infrastructure used for support of
MPLS/GMPLS is to separate the resources for support of MPLS/GMPLS MPLS/GMPLS is to separate the resources for support of MPLS/GMPLS
services from the resources used for other purposes (such as services from the resources used for other purposes (such as
support of Internet services). In some cases this may use support of Internet services). In some cases this may involve using
physically separate equipment for VPN services, or even a physically separate equipment for VPN services, or even a
physically separate network. physically separate network.
For example, PE-based IP VPNs may be run on a separate backbone not For example, PE-based IP VPNs may be run on a separate backbone not
connected to the Internet, or may make use of separate edge routers connected to the Internet, or may use separate edge routers from
from those used to support Internet service. Private IP addresses those supporting Internet service. Private IPv4 addresses (local to
(local to the provider and non-routable over the Internet) are the provider and non-routable over the Internet) are sometimes used
sometimes used to provide additional separation. to provide additional separation. For a discussion of comparable
techniques for IPv6, see "Local Network Protection for IPv6," RFC
4864 [RFC4864].
In a GMPLS network it is possible to operate the control plane using In a GMPLS network it is possible to operate the control plane using
physically separate resources form those used for the data plane. physically separate resources from those used for the data plane.
This means that the data plane resources can be physically protected This means that the data plane resources can be physically protected
and isolated from other equipment to protect the data while the and isolated from other equipment to protect users' data while the
control and management traffic uses network resources that can be control and management traffic uses network resources that can be
accessed by operators so as to configure the network. Conversely, accessed by operators to configure the network. Conversely, the
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November 2008
the separation of control and data traffic may lead the operator to
consider that the network is secure because the data plane resources consider that the network is secure because the data plane resources
are physically secure - but this is not the case if the control are physically secure. However, this is not the case if the control
MPLS/GMPLS Security framework
plane can be attacked through a shared or open network, and control plane can be attacked through a shared or open network, and control
plane protection techniques must still be applied. plane protection techniques must still be applied.
5.5. Use of Aggregated Infrastructure 5.5. Use of Aggregated Infrastructure
In general, it is not feasible to use a completely separate set of In general, it is not feasible to use a completely separate set of
resources for support of each service. In fact, one of the main resources for support of each service. In fact, one of the main
reasons for MPLS/GMPLS enabled services is to allow sharing of reasons for MPLS/GMPLS enabled services is to allow sharing of
resources between multiple services and multiple users. Thus, even resources between multiple services and multiple users. Thus, even
if certain services make use of a separate network from Internet if certain services use a separate network from Internet services,
services, nonetheless there will still be multiple MPLS/GMPLS users nonetheless there will still be multiple MPLS/GMPLS users sharing
sharing the same network resources. In some cases MPLS/GMPLS the same network resources. In some cases MPLS/GMPLS services will
services will share the use of network resources with Internet share network resources with Internet services or other services.
services or other services.
It is therefore important for MPLS/GMPLS services to provide It is therefore important for MPLS/GMPLS services to provide
protection between resources used by different parties. Thus a protection between resources used by different parties. Thus, a
well-behaved MPLS/GMPLS user should be protected from possible well-behaved MPLS/GMPLS user should be protected from possible
misbehavior by other users. This requires several security misbehavior by other users. This requires several security
measurements to be implemented. Resource limits can be placed on measurements to be implemented. Resource limits can be placed on a
per service and per user basis. For example, using virtual router per service and per user basis. Possibilities include, for example,
or logical router to define hardware or software resource limits using virtual router or logical router to define hardware or
per service or per individual user; using rate limiting per VPN or software resource limits per service or per individual user; using
per Internet connection to provide bandwidth protection; using rate limiting per VPN or per Internet connection to provide
resource reservation for control plane traffic. In addition to bandwidth protection; or using resource reservation for control
bandwidth protection, separate resource allocation can be used to plane traffic. In addition to bandwidth protection, separate
limit security attacks only to directly impacted service(s) or resource allocation can be used to limit security attacks only to
customer(S). Strict, separate, and clearly defined engineering directly impacted service(s) or customer(s). Strict, separate, and
rules and provisioning procedures can reduce the risks of network clearly defined engineering rules and provisioning procedures can
wide impact through control plane attack, DoS attack, or mis- reduce the risks of network-wide impact of a control plane attack,
configurations. DoS attack, or mis-configuration.
In general, the use of aggregated infrastructure allows the service In general, the use of aggregated infrastructure allows the service
provider to benefit from stochastic multiplexing of multiple bursty provider to benefit from stochastic multiplexing of multiple bursty
flows, and also may in some cases thwart traffic pattern analysis flows, and also may in some cases thwart traffic pattern analysis
by combining the data from multiple users. However, service by combining the data from multiple users. However, service
providers must minimize security risks introduced from any providers must minimize security risks introduced from any
individual service or individual users. individual service or individual users.
5.6. Service Provider Quality Control Processes 5.6. Service Provider Quality Control Processes
Deployment of provider-provisioned VPN services in general requires Deployment of provider-provisioned VPN services in general requires
a relatively large amount of configuration by the SP. For example, a relatively large amount of configuration by the SP. For example,
the SP needs to configure which VPN each site belongs to, as well the SP needs to configure which VPN each site belongs to, as well
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November 2008
as QoS and SLA guarantees. This large amount of required as QoS and SLA guarantees. This large amount of required
configuration leads to the possibility of misconfiguration. configuration leads to the possibility of misconfiguration.
MPLS/GMPLS Security framework
It is important for the SP to have operational processes in place It is important for the SP to have operational processes in place
to reduce the potential impact of misconfiguration. CE-to-CE to reduce the potential impact of misconfiguration. CE-to-CE
authentication may also be used to detect misconfiguration when it authentication may also be used to detect misconfiguration when it
occurs. CE-to-CE encryption may also limit the damage when it
occurs. occurs.
5.7. Deployment of Testable MPLS/GMPLS Service. 5.7. Deployment of Testable MPLS/GMPLS Service.
This refers to solutions that can be readily tested to make sure This refers to solutions that can be readily tested to make sure
they are configured correctly. For example, for a point-point they are configured correctly. For example, for a point-to-point
connection, checking that the intended connectivity is working connection, checking that the intended connectivity is working
pretty much ensures that there is not connectivity to some pretty much ensures that there is no unintended connectivity to
unintended site. some other site.
5.8. Verification of Connectivity 5.8. Verification of Connectivity
In order to protect against deliberate or accidental misconnection, In order to protect against deliberate or accidental misconnection,
mechanisms can be put in place to verify both end-to-end mechanisms can be put in place to verify both end-to-end
connectivity and hop-by-hop resources. These mechanisms can trace connectivity and hop-by-hop resources. These mechanisms can trace
the routes of LSPs in both the control plane and the data plane. the routes of LSPs in both the control plane and the data plane.
It should be noted that where there is an attack on the control It should be noted that if there is an attack on the control plane,
plane it may be that data plane connectivity test mechanisms that data plane connectivity test mechanisms that rely on the control
utilize the control plane can also be attacked to hide faults plane can also be attacked. This may hide faults through false
through false positives, or to disrupt functioning services through positives or to disrupt functioning services through false
false negatives. negatives.
6. Monitoring, Detection, and Reporting of Security Attacks 6. Monitoring, Detection, and Reporting of Security Attacks
MPLS/GMPLS network and service may be subject to attacks from a MPLS/GMPLS network and service may be subject to attacks from a
variety of security threats. Many threats are described in another variety of security threats. Many threats are described in Section
part of this document. Many of the defensive techniques described 4 of this document. Many of the defensive techniques described in
in this document and elsewhere provide significant levels of this document and elsewhere provide significant levels of
protection from a variety of threats. However, in addition to protection from a variety of threats. However, in addition to
silently employing defensive techniques to protect against attacks, employing defensive techniques silently to protect against attacks,
MPLS/GMPLS services can also add value for both providers and MPLS/GMPLS services can also add value for both providers and
customers by implementing security monitoring systems to detect and customers by implementing security monitoring systems to detect and
report on any security attacks which occur, regardless of whether report on any security attacks, regardless of whether the attacks
the attacks are effective. are effective.
Attackers often begin by probing and analyzing defenses, so systems Attackers often begin by probing and analyzing defenses, so systems
that can detect and properly report these early stages of attacks that can detect and properly report these early stages of attacks
can provide significant benefits. can provide significant benefits.
Information concerning attack incidents, especially if available Information concerning attack incidents, especially if available
quickly, can be useful in defending against further attacks. It quickly, can be useful in defending against further attacks. It
MPLS/GMPLS Security framework
November 2008
can be used to help identify attackers or their specific targets at can be used to help identify attackers or their specific targets at
an early stage. This knowledge about attackers and targets can be an early stage. This knowledge about attackers and targets can be
MPLS/GMPLS Security framework
used to strengthen defenses against specific attacks or attackers, used to strengthen defenses against specific attacks or attackers,
or improve the defensive services for specific targets on an as- or to improve the defenses for specific targets on an as-needed
needed basis. Information collected on attacks may also be useful basis. Information collected on attacks may also be useful in
in identifying and developing defenses against novel attack types. identifying and developing defenses against novel attack types.
Monitoring systems used to detect security attacks in MPLS/GMPLS Monitoring systems used to detect security attacks in MPLS/GMPLS
typically operate by collecting information from the Provider Edge typically operate by collecting information from the Provider Edge
(PE), Customer Edge (CE), and/or Provider backbone (P) devices. (PE), Customer Edge (CE), and/or Provider backbone (P) devices.
Security monitoring systems should have the ability to actively Security monitoring systems should have the ability to actively
retrieve information from devices (e.g., SNMP get) or to passively retrieve information from devices (e.g., SNMP get) or to passively
receive reports from devices (e.g., SNMP notifications). The receive reports from devices (e.g., SNMP notifications). The
specific information exchanged depends on the capabilities of the Security monitoring systems may actively retrieve information from
devices and on the type of VPN technology. Particular care should devices (e.g., SNMP get) or passively receive reports from devices
be given to securing the communications channel between the (e.g., SNMP notifications). The specific information exchanged
monitoring systems and the MPLS/GMPLS devices. Syslog WG is depends on the capabilities of the devices and on the type of VPN
specifying "Logging Capabilities for IP Network Infrastructure". technology. Particular care should be given to securing the
(The specific references will be made only if the draft(s) became communications channel between the monitoring systems and the
RFC before this draft.) MPLS/GMPLS devices. Syslog WG is specifying "Logging Capabilities
for IP Network Infrastructure". (The specific references will be
made only if the draft(s) became RFC before this draft.)
The CE, PE, and P devices should employ efficient methods to The CE, PE, and P devices should employ efficient methods to
acquire and communicate the information needed by the security acquire and communicate the information needed by the security
monitoring systems. It is important that the communication method monitoring systems. It is important that the communication method
between MPLS/GMPLS devices and security monitoring systems be between MPLS/GMPLS devices and security monitoring systems be
designed so that it will not disrupt network operations. As an designed so that it will not disrupt network operations. As an
example, multiple attack events may be reported through a single example, multiple attack events may be reported through a single
message, rather than allowing each attack event to trigger a message, rather than allowing each attack event to trigger a
separate message, which might result in a flood of messages, separate message, which might result in a flood of messages,
essentially becoming a denial-of-service attack against the essentially becoming a DoS attack against the monitoring system or
monitoring system or the network. the network.
The mechanisms for reporting security attacks should be flexible The mechanisms for reporting security attacks should be flexible
enough to meet the needs of MPLS/GMPLS service providers, enough to meet the needs of MPLS/GMPLS service providers,
MPLS/GMPLS customers, and regulatory agencies, if applicable. The MPLS/GMPLS customers, and regulatory agencies, if applicable. The
specific reports should depend on the capabilities of the devices, specific reports should depend on the capabilities of the devices,
the security monitoring system, the type of VPN, and the service the security monitoring system, the type of VPN, and the service
level agreements between the provider and customer. level agreements between the provider and customer.
7. Service Provider General Security Requirements 7. Service Provider General Security Requirements
This section covers security requirements the provider may have for This section covers security requirements the provider may have for
securing its MPLS/GMPLS network infrastructure including LDP and securing its MPLS/GMPLS network infrastructure including LDP and
RSVP-TE specific requirements. RSVP-TE specific requirements.
The MPLS/GMPLS service provider's requirements defined here are for The MPLS/GMPLS service provider's requirements defined here are for
the MPLS/GMPLS core in the reference model. The core network can the MPLS/GMPLS core in the reference model. The core network can
be implemented with different types of network technologies, and be implemented with different types of network technologies, and
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November 2008
each core network may use different technologies to provide the each core network may use different technologies to provide the
various services to users with different levels of offered various services to users with different levels of offered
security. Therefore, a MPLS/GMPLS service provider may fulfill any security. Therefore, a MPLS/GMPLS service provider may fulfill any
number of the security requirements listed in this section. This number of the security requirements listed in this section. This
document does not state that a MPLS/GMPLS network must fulfill all document does not state that a MPLS/GMPLS network must fulfill all
of these requirements to be secure. of these requirements to be secure.
These requirements are focused on: 1) how to protect the MPLS/GMPLS These requirements are focused on: 1) how to protect the MPLS/GMPLS
core from various attacks outside the core including network users, core from various attacks originating outside the core including
both accidentally and maliciously, 2) how to protect the end users. those from network users, both accidentally and maliciously, and 2)
how to protect the end users.
7.1. Protection within the Core Network 7.1. Protection within the Core Network
7.1.1. Control Plane Protection - General 7.1.1. Control Plane Protection - General
- Protocol authentication within the core: - Protocol authentication within the core:
The network infrastructure must support mechanisms for The network infrastructure must support mechanisms for
authentication of the control plane. If MPLS/GMPLS core is used, authentication of the control plane messages. If a MPLS/GMPLS core
LDP sessions may be authenticated by use TCP MD5, in addition, IGP is used, LDP sessions may be authenticated with TCP MD5. In
and BGP authentication should also be considered. For a core addition, IGP and BGP authentication should be considered. For a
providing various IP, VPN, or transport services, PE-to-PE core providing various IP, VPN, or transport services, PE-to-PE
authentication may also be performed via IPsec. See the above authentication may also be performed via IPsec. See the above
discussion of protocol security services: authentication, integrity discussion of protocol security services: authentication, integrity
(with replay detection), confidentiality. Protocols need to provide (with replay detection), confidentiality. Protocols need to provide
a complete set of security services from which the SP can choose. a complete set of security services from which the SP can choose.
Also, the hard but very important part is key management. Also, the important but often harder part is key management.
Considerations, Guidelines, and strategies regarding key management Considerations, guidelines, and strategies regarding key management
were discussed in [RFC3562], [RFC4107], [RFC4808]. are discussed in [RFC3562], [RFC4107], [RFC4808].
With the cost of authentication coming down rapidly, the With today's processors, applying cryptograpgic authentication to
application of control plane authentication may not increase the the control plane may not increase the cost of deployment for
cost of implementation for providers significantly, and will help providers significantly, and will help to improve the security of
to improve the security of the core. If the core is dedicated to the core. If the core is dedicated to MPLS/GMPLS enabled services
MPLS/GMPLS enabled services and without any interconnects to third without any interconnects to third parties, then this may reduce
parties then this may reduce the requirement for authentication of the requirement for authentication of the core control plane.
the core control plane.
- Infrastructure Hiding - Infrastructure Hiding
Here we discuss means to hide the provider's infrastructure nodes. Here we discuss means to hide the provider's infrastructure nodes.
A MPLS/GMPLS provider may make its infrastructure routers (P and PE A MPLS/GMPLS provider may make its infrastructure routers (P and PE
routers) unreachable from outside users and unauthorized internal routers) unreachable from outside users and unauthorized internal
users. For example, separate address space may be used for the users. For example, separate address space may be used for the
infrastructure loopbacks. infrastructure loopbacks.
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November 2008
Normal TTL propagation may be altered to make the backbone look Normal TTL propagation may be altered to make the backbone look
like one hop from the outside, but caution needs to be taken for like one hop from the outside, but caution needs to be taken for
loop prevention. This prevents the backbone addresses from being loop prevention. This prevents the backbone addresses from being
exposed through trace route; however this must also be assessed exposed through trace route; however this must also be assessed
against operational requirements for end-to-end fault tracing. against operational requirements for end-to-end fault tracing.
An Internet backbone core may be re-engineered to make Internet An Internet backbone core may be re-engineered to make Internet
routing an edge function, for example, by using MPLS label routing an edge function, for example, by using MPLS label
switching for all traffic within the core and possibly make the switching for all traffic within the core and possibly making the
Internet a VPN within the PPVPN core itself. This helps to detach Internet a VPN within the PPVPN core itself. This helps to detach
Internet access from PPVPN services. Internet access from PPVPN services.
Separating control plane, data plane, and management plane Separating control plane, data plane, and management plane
functionality in hardware and software may be implemented on the PE functionality in hardware and software may be implemented on the PE
devices to improve security. This may help to limit the problems devices to improve security. This may help to limit the problems
when attacked in one particular area, and may allow each plane to when attacked in one particular area, and may allow each plane to
implement additional security measures separately. implement additional security measures separately.
PEs are often more vulnerable to attack than P routers, because PEs PEs are often more vulnerable to attack than P routers, because PEs
cannot be made unreachable from outside users by their very nature. cannot be made unreachable from outside users by their very nature.
Access to core trunk resources can be controlled on a per user Access to core trunk resources can be controlled on a per user
basis by using of inbound rate-limiting or traffic shaping; this basis by using of inbound rate-limiting or traffic shaping; this
can be further enhanced on a per Class of Service basis (see can be further enhanced on a per Class of Service basis (see
Section 8.2.3) Section 8.2.3)
In the PE, using separate routing processes for different services, In the PE, using separate routing processes for different services,
for example, Internet and PPVPN service, may help to improve the for example, Internet and PPVPN service, may help to improve the
PPVPN security and better protect VPN customers. Furthermore, if PPVPN security and better protect VPN customers. Furthermore, if
resources, such as CPU and Memory, can be further separated based resources, such as CPU and memory, can be further separated based
on applications, or even individual VPNs, it may help to provide on applications, or even individual VPNs, it may help to provide
improved security and reliability to individual VPN customers. improved security and reliability to individual VPN customers.
7.1.2. Control plane protection with RSVP-TE 7.1.2. Control Plane Protection with RSVP-TE
- General RSVP Security Tools - General RSVP Security Tools
Isolation of the trusted domain is an important security mechanism Isolation of the trusted domain is an important security mechanism
for RSVP, to ensure that an untrusted element cannot access a for RSVP, to ensure that an untrusted element cannot access a
router of the trusted domain. However, ASBR-ASBR communication for router of the trusted domain. However, ASBR-ASBR communication for
inter-AS LSPs needs to be secured specifically. Isolation inter-AS LSPs needs to be secured specifically. Isolation
mechanisms might also be bypassed by Router Alert IP packets. A mechanisms might also be bypassed by IPv4 Router Alert or IPv6
solution could consists of disabling the processing of IP options. using Next Header 0 packets. A solution could consists of disabling
This drops or ignores all IP packets with IP options, including the the processing of IP options. This drops or ignores all IP packets
router alert option used by RSVP; however, this may have an impact with IPv4 options, including the router alert option used by RSVP;
on other protocols using IP options. An alternative is to configure however, this may have an impact on other protocols using IPv4
access-lists on all incoming interfaces dropping IP protocol 46 options. An alternative is to configure access-lists on all
incoming interfaces dropping IPv4 protocol or IPv6 next header 46
(RSVP). (RSVP).
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November 2008
RSVP security can be strengthened by deactivating RSVP on RSVP security can be strengthened by deactivating RSVP on
interfaces with neighbors who are not authorized to use RSVP, to interfaces with neighbors who are not authorized to use RSVP, to
protect against adjacent CE-PE attacks. However, this does not protect against adjacent CE-PE attacks. However, this does not
really protect against DoS attacks or attacks on non-adjacent really protect against DoS attacks or attacks on non-adjacent
routers. It has been demonstrated that substantial CPU resources routers. It has been demonstrated that substantial CPU resources
are consumed simply by processing received RSVP packets, even if are consumed simply by processing received RSVP packets, even if
the RSVP process is deactivated for the specific interface on which the RSVP process is deactivated for the specific interface on which
the RSVP packets are received. the RSVP packets are received.
RSVP neighbor filtering at the protocol level, to restrict the set RSVP neighbor filtering at the protocol level, to restrict the set
of neighbors that can send RSVP messages to a given router, of neighbors that can send RSVP messages to a given router,
protects against non-adjacent attacks. However, this does not protects against non-adjacent attacks. However, this does not
protect against DoS attacks and does not effectively protect protect against DoS attacks and does not effectively protect
against spoofing of the source address of RSVP packets, if the against spoofing of the source address of RSVP packets, if the
filter relies on the neighbor's address within the RSVP message. filter relies on the neighbor's address within the RSVP message.
RSVP neighbor filtering at the data plane level - with an access RSVP neighbor filtering at the data plane level, with an access
list to accept IP packets with port 46, only for specific list to accept IP packets with port 46 only for specific neighbors
neighbors. This requires Router Alert mode to be deactivated and requires Router Alert mode to be deactivated and does not protect
does not protect against spoofing. against spoofing.
Another valuable tool is RSVP message pacing, to limit the number Another valuable tool is RSVP message pacing, to limit the number
of RSVP messages sent to a given neighbor during a given period. of RSVP messages sent to a given neighbor during a given period.
This allows blocking DoS attack propagation. This allows blocking DoS attack propagation.
- limit the impact of an attack on control plane resources - Another approach is to limit the impact of an attack on control
plane resources.
To ensure continued effective operation of the MPLS router even in To ensure continued effective operation of the MPLS router even in
the case of an attack that bypasses packet filtering mechanisms the case of an attack that bypasses packet filtering mechanisms
such as Access Control Lists in the data plane, it is important such as Access Control Lists in the data plane, it is important
that routers have some mechanisms to limit the impact of the that routers have some mechanisms to limit the impact of the
attack. There should be a mechanism to rate limit the amount of attack. There should be a mechanism to rate limit the amount of
control plane traffic addressed to the router, per interface. This control plane traffic addressed to the router, per interface. This
should be configurable on a per-protocol basis, (and, ideally, on a should be configurable on a per-protocol basis, (and, ideally, on a
per-sender basis) to avoid letting an attacked protocol or a given per-sender basis) to avoid letting an attacked protocol or a given
sender blocking all communications. This requires the ability to sender blocking all communications. This requires the ability to
filter and limit the rate of incoming messages of particular filter and limit the rate of incoming messages of particular
protocols, such as RSVP (filtering at the IP protocol level), and protocols, such as RSVP (filtering at the IP protocol level), and
particular senders. In addition, there should be a mechanism to particular senders. In addition, there should be a mechanism to
limit CPU and memory capacity allocated to RSVP, so as to protect limit CPU and memory capacity allocated to RSVP, so as to protect
other control plane elements. To limit the memory allocation, it other control plane elements. To limit memory allocation, it will
will probably be necessary to limit the number of LSPs that can be probably be necessary to limit the number of LSPs that can be set
set up. up.
- Authentication for RSVP messages - Authentication for RSVP messages
MPLS/GMPLS Security framework
RSVP message authentication is described in RFC 2747 [RFC2747] and RSVP message authentication is described in RFC 2747 [RFC2747] and
RFC 3097 [RFC3097]. It is one of the most powerful tools for RFC 3097 [RFC3097]. It is one of the most powerful tools for
MPLS/GMPLS Security framework protection against RSVP-based attacks. It applies cryptographic
November 2008 authentication to RSVP messages based on a secure message hash
using a key shared by RSVP neighbors. This protects against LSP
protection against RSVP-based attacks is the use of authentication creation attacks, at the expense of consuming significant CPU
for RSVP messages, based on a secure message hash using a key resources for digest computation. In addition, if the neighboring
shared by RSVP neighbors. This protects against LSP creation RSVP speaker is compromised, it could be used to launch attacks
attacks, at the expense of consuming significant CPU resources for using authenticated RSVP messages. These methods, and certain other
digest computation. In addition, if the neighboring RSVP speaker
is compromised, it could be used to launch attacks using
authenticated RSVP messages. These methods, and certain other
aspects of RSVP security, are explained in detail in RFC 4230 aspects of RSVP security, are explained in detail in RFC 4230
[RFC4230]. Key management must be implemented. Logging and auditing [RFC4230]. Key management must be implemented. Logging and auditing
as well as multiple layers of crypto protection can help here. as well as multiple layers of cryptographic protection can help
IPsec can also be used. here. IPsec can also be used in some cases. See [RFC4230]..
One challenge using RSVP message authentication arises in many One challenge using RSVP message authentication arises in many
cases where non-RSVP nodes are present in the network. In such cases where non-RSVP nodes are present in the network. In such
cases the RSVP neighbor may not be known up front, thus neighbor cases the RSVP neighbor may not be known up front, thus neighbor
based keying approaches fail, unless the same key is used based keying approaches fail, unless the same key is used
everywhere, which is not recommended for security reasons. Group everywhere, which is not recommended for security reasons. Group
keying may help in such cases. The security properties of various keying may help in such cases. The security properties of various
keying approaches are discussed in detail in [RSVP-key]. keying approaches are discussed in detail in [RSVP-key].
7.1.3. Control plane protection with LDP 7.1.3. Control Plane Protection with LDP
The approaches to protect MPLS routers against LDP-based attacks The approaches to protect MPLS routers against LDP-based attacks
are similar to those for RSVP, including isolation, protocol are similar to those for RSVP, including isolation, protocol
deactivation on specific interfaces, filtering of LDP neighbors at deactivation on specific interfaces, filtering of LDP neighbors at
the protocol level, filtering of LDP neighbors at the data plane the protocol level, filtering of LDP neighbors at the data plane
level (access list that filter the TCP & UDP LDP ports), level (with an access list that filters the TCP and UDP LDP ports),
authentication with message digest, rate limiting of LDP messages authentication with a message digest, rate limiting of LDP messages
per protocol per sender and limiting all resources allocated to per protocol per sender, and limiting all resources allocated to
LDP-related tasks. LDP-related tasks.
7.1.4. Data Plane Protection 7.1.4. Data Plane Protection
IPsec can provide authentication, integrity, confidentiality, and IPsec can provide authentication, integrity, confidentiality, and
replay detection for provider or user data. It also has an replay detection for provider or user data. It also has an
associated key management protocol. associated key management protocol.
In today's MPLS/GMPLS, ATM, or Frame Relay networks, encryption is In today's MPLS/GMPLS, ATM, or Frame Relay networks, encryption is
not provided as a basic feature. Mechanisms described in section 5 not provided as a basic feature. Mechanisms described in section 5
can be used to secure the MPLS data plane traffic carried over MPLS can be used to secure the MPLS data plane traffic carried over a
core. Both the Frame Relay Forum and the ATM Forum standardized MPLS core. Both the Frame Relay Forum and the ATM Forum
cryptographic security services in the late 1990s, but these standardized cryptographic security services in the late 1990s, but
standards are not widely implemented. these standards are not widely implemented.
7.2. Protection on the User Access Link
MPLS/GMPLS Security framework MPLS/GMPLS Security framework
November 2008 7.2. Protection on the User Access Link
Peer or neighbor protocol authentication may be used to enhance Peer or neighbor protocol authentication may be used to enhance
security. For example, BGP MD5 authentication may be used to security. For example, BGP MD5 authentication may be used to
enhance security on PE-CE links using eBGP. In the case of Inter- enhance security on PE-CE links using eBGP. In the case of Inter-
provider connection, cryptographic protection mechanisms between provider connections, cryptographic protection mechanisms, such as
ASes, such as IPsec, may be used. IPsec, may be used between ASes.
If multiple services are provided on the same PE platform, If multiple services are provided on the same PE platform,
different WAN address spaces may be used for different services different WAN address spaces may be used for different services
(e.g., VPN and non-VPN) to enhance isolation. (e.g., VPN and non-VPN) to enhance isolation.
Firewall and Filtering: access control mechanisms can be used to Firewall and Filtering: access control mechanisms can be used to
filter any packets destined for the service provider's filter any packets destined for the service provider's
infrastructure prefix or eliminate routes identified as infrastructure prefix or eliminate routes identified as
illegitimate. illegitimate.
Rate limiting may be applied to the user interface/logical Rate limiting may be applied to the user interface/logical
interfaces against DDoS bandwidth attack. This is helpful when the interfaces as a defense against DDoS bandwidth attack. This is
PE device is supporting both multi-services, especially VPN and helpful when the PE device is supporting both multiple services,
Internet Services, on the same physical interfaces through especially VPN and Internet Services, on the same physical
different logical interfaces. interfaces through different logical interfaces.
7.2.1. Link Authentication 7.2.1. Link Authentication
Authentication can be used to validate site access to the network Authentication can be used to validate site access to the network
via fixed or logical connections, e.g. L2TP, IPsec, respectively. via fixed or logical connections, e.g., L2TP or IPsec,
If the user wishes to hold the authentication credentials for respectively. If the user wishes to hold the authentication
access, then provider solutions require the flexibility for either credentials for access, then provider solutions require the
direct authentication by the PE itself or interaction with a flexibility for either direct authentication by the PE itself or
customer authentication server. Mechanisms are required in the interaction with a customer authentication server. Mechanisms are
latter case to ensure that the interaction between the PE and the required in the latter case to ensure that the interaction between
customer authentication server is appropriately secured. the PE and the customer authentication server is appropriately
secured.
7.2.2. Access Routing Control 7.2.2. Access Routing Control
Routing protocol level e.g., RIP, OSPF, or BGP, may be used to Choice of routing protocols, e.g., RIP, OSPF, or BGP, may be used
provide control access between a CE and PE. Per neighbor and per to provide control access between a CE and a PE. Per neighbor and
VPN routing policies may be established to enhance security and per VPN routing policies may be established to enhance security and
reduce the impact of a malicious or non-malicious attack on the PE; reduce the impact of a malicious or non-malicious attack on the PE;
the following mechanisms, in particular, should be considered: the following mechanisms, in particular, should be considered:
- Limiting the number of prefixes that may be advertised on - Limiting the number of prefixes that may be advertised on
a per access basis into the PE. Appropriate action may be a per access basis into the PE. Appropriate action may be
taken should a limit be exceeded, e.g., the PE shutting taken should a limit be exceeded, e.g., the PE shutting
down the peer session to the CE down the peer session to the CE
- Applying route dampening at the PE on received routing - Applying route dampening at the PE on received routing
updates updates
MPLS/GMPLS Security framework
- Definition of a per VPN prefix limit after which - Definition of a per VPN prefix limit after which
additional prefixes will not be added to the VPN routing additional prefixes will not be added to the VPN routing
table. table.
MPLS/GMPLS Security framework
November 2008
In the case of Inter-provider connection, access protection, link In the case of Inter-provider connection, access protection, link
authentication, and routing policies as described above may be authentication, and routing policies as described above may be
applied. Both inbound and outbound firewall or filtering mechanism applied. Both inbound and outbound firewall or filtering mechanism
between ASes may be applied. Proper security procedures must be between ASes may be applied. Proper security procedures must be
implemented in Inter-provider interconnection to protect the implemented in Inter-provider interconnection to protect the
providers' network infrastructure and their customers. This may be providers' network infrastructure and their customers. This may be
custom designed for each Inter-Provider peering connection, and custom designed for each Inter-Provider peering connection, and
must be agreed upon by both providers. must be agreed upon by both providers.
7.2.3. Access QoS 7.2.3. Access QoS
MPLS/GMPLS providers offering QoS-enabled services require MPLS/GMPLS providers offering QoS-enabled services require
mechanisms to ensure that individual accesses are validated against mechanisms to ensure that individual accesses are validated against
their subscribed QOS profile and as such gain access to core their subscribed QoS profile and as such gain access to core
resources that match their service profile. Mechanisms such as per resources that match their service profile. Mechanisms such as per
Class of Service rate limiting or traffic shaping on ingress to the Class of Service rate limiting or traffic shaping on ingress to the
MPLS/GMPLS core are one option for providing this level of control. MPLS/GMPLS core are two options for providing this level of
Such mechanisms may require the per Class of Service profile to be control. Such mechanisms may require the per Class of Service
enforced either by marking, or remarking or discard of traffic profile to be enforced either by marking, or remarking, or
outside of the profile. discarding of traffic outside of the profile.
7.2.4. Customer service monitoring tools 7.2.4. Customer Service Monitoring Tools
End users requiring specific statistics on the core, e.g., routing End users needing specific statistics on the core, e.g., routing
table, interface status, or QoS statistics, requirements for table, interface status, or QoS statistics, place requirements on
mechanisms at the PE both to validate the incoming user and limit mechanisms at the PE both to validate the incoming user and limit
the views available to that particular user. Mechanisms should the views available to that particular user. Mechanisms should
also be considered to ensure that such access cannot be used a also be considered to ensure that such access cannot be used as
means of a DoS attack (either malicious or accidental) on the PE means to construct DoS attack (either maliciously or accidentally)
itself. This could be accomplished through either separation of on the PE itself. This could be accomplished either through
these resources within the PE itself or via the capability to rate- separation of these resources within the PE itself or via the
limit on a per physical or logical connection basis such traffic. capability to rate-limit such traffic on a per physical or logical
connection basis.
7.3. General User Requirements for MPLS/GMPLS Providers 7.3. General User Requirements for MPLS/GMPLS Providers
MPLS/GMPLS providers must support end users' security requirements. MPLS/GMPLS providers must support end users' security requirements.
Depending on the technologies used, these requirements may include: Depending on the technologies used, these requirements may include:
- User control plane separation - routing isolation when - User control plane separation through routing isolation
applicable, for example, in the case of MPLS VPNs. when applicable, for example, in the case of MPLS VPNs.
- Protection against intrusion, DoS attacks and spoofing - Protection against intrusion, DoS attacks, and spoofing
- Access Authentication - Access Authentication
- Techniques highlighted through this document that identify
methodologies for the protection of resources and the
MPLS/GMPLS infrastructure.
MPLS/GMPLS Security framework MPLS/GMPLS Security framework
November 2008 - Techniques highlighted throughout this document that
identify methodologies for the protection of resources and
the MPLS/GMPLS infrastructure.
Hardware or software errors in equipment leading to breaches in Hardware or software errors in equipment leading to breaches in
security are not within the scope of this document. security are not within the scope of this document.
8. Inter-provider Security Requirements 8. Inter-provider Security Requirements
This section discusses security capabilities that are important at This section discusses security capabilities that are important at
the MPLS/GMPLS Inter-provider connections and at devices (including the MPLS/GMPLS Inter-provider connections and at devices (including
ASBR routers) supporting these connections. The security ASBR routers) supporting these connections. The security
capabilities stated in this section should be considered as capabilities stated in this section should be considered as
skipping to change at page 43, line 26 skipping to change at page 44, line 27
capabilities stated in this section should be considered as capabilities stated in this section should be considered as
complementary to security considerations addressed in individual complementary to security considerations addressed in individual
protocol specifications or security frameworks. protocol specifications or security frameworks.
Security vulnerabilities and exposures may be propagated across Security vulnerabilities and exposures may be propagated across
multiple networks because of security vulnerabilities arising in multiple networks because of security vulnerabilities arising in
one peer's network. Threats to security originate from accidental, one peer's network. Threats to security originate from accidental,
administrative, and intentional sources. Intentional threats administrative, and intentional sources. Intentional threats
include events such as spoofing and Denial of Service (DoS) include events such as spoofing and Denial of Service (DoS)
attacks. attacks.
The level and nature of threats, as well as security and The level and nature of threats, as well as security and
availability requirements, may vary over time and from network to availability requirements, may vary over time and from network to
network. This section therefore discusses capabilities that need to network. This section, therefore, discusses capabilities that need
be available in equipment deployed for support of the MPLS to be available in equipment deployed for support of the MPLS
InterCarrier Interconnect (MPLS-ICI). Whether any particular InterCarrier Interconnect (MPLS-ICI). Whether any particular
capability is used in any one specific instance of the ICI is up to capability is used in any one specific instance of the ICI is up to
the service providers managing the PE equipment offering/using the the service providers managing the PE equipment offering or using
ICI services. the ICI services.
8.1. Control Plane Protection 8.1. Control Plane Protection
This section discusses capabilities for control plane protection, This section discusses capabilities for control plane protection,
including protection of routing, signaling, and OAM capabilities. including protection of routing, signaling, and OAM capabilities.
8.1.1. Authentication of Signaling Sessions 8.1.1. Authentication of Signaling Sessions
Authentication may be needed for signaling sessions (i.e., BGP, LDP Authentication may be needed for signaling sessions (i.e., BGP,
and RSVP-TE) and routing sessions (e.g., BGP) as well as OAM LDP, and RSVP-TE) and routing sessions (e.g., BGP), as well as OAM
sessions across domain boundaries. Equipment must be able to sessions across domain boundaries. Equipment must be able to
support exchange of all protocol messages over IPsec, with NULL support the exchange of all protocol messages over IPsec ESP, with
encryption and authentication, between the peering ASBRs. Support NULL encryption and authentication, between the peering ASBRs.
for message authentication for LDP, BGP and RSVP-TE authentication Support for message authentication for LDP, BGP, and RSVP-TE
must also be provided. Manual keying of IPsec should not be used. authentication must also be provided. Manual keying of IPsec should
IKEv2 with pre-shared secrets or public key methods should be used. MPLS/GMPLS Security framework
Replay detection should be used. not be used. IKEv2 with pre-shared secrets or public key methods
should be used. Replay detection should be used.
Mechanisms to authenticate and validate a dynamic setup request Mechanisms to authenticate and validate a dynamic setup request
MUST be available. For instance, if dynamic signaling of a TE-LSP must be available. For instance, if dynamic signaling of a TE-LSP
or PW is crossing a domain boundary, there must be a way to detect or PW is crossing a domain boundary, there must be a way to detect
MPLS/GMPLS Security framework whether the LSP source is who it claims to be and that it is
November 2008
whether the LSP source is who it claims to be and that he is
allowed to connect to the destination. allowed to connect to the destination.
Message authentication support for all TCP-based protocols within Message authentication support for all TCP-based protocols within
the scope of the MPLS-ICI (i.e., LDP signaling and BGP routing) and the scope of the MPLS-ICI (i.e., LDP signaling and BGP routing) and
Message authentication with the RSVP-TE Integrity Object MUST be Message authentication with the RSVP-TE Integrity Object must be
provided to interoperate with current practices. provided to interoperate with current practices.
Equipment SHOULD be able to support exchange of all signaling and Equipment should be able to support exchange of all signaling and
routing (LDP, RSVP-TE, and BGP) protocol messages over a single routing (LDP, RSVP-TE, and BGP) protocol messages over a single
IPSec security association pair in tunnel or transport mode with IPsec security association pair in tunnel or transport mode with
authentication but with NULL encryption, between the peering ASBRs. authentication but with NULL encryption, between the peering ASBRs.
IPSec, if supported, must be supported with HMAC-MD5 and optionally IPsec, if supported, must be supported with HMAC-SHA-1 and
SHA-1. It is expected that authentication algorithms will evolve alternatively with HMAC-SHA-2 and optionally SHA-1. It is expected
over time and support can be updated as needed. that authentication algorithms will evolve over time and support
can be updated as needed.
OAM Operations across the MPLS-ICI could also be the source of OAM Operations across the MPLS-ICI could also be the source of
security threats on the provider infrastructure as well as the security threats on the provider infrastructure as well as the
service offered over the MPLS-ICI. A large volume of OAM messages service offered over the MPLS-ICI. A large volume of OAM messages
could overwhelm the processing capabilities of an ASBR if the ASBR could overwhelm the processing capabilities of an ASBR if the ASBR
is not properly protected. Maliciously generated OAM messages could is not properly protected. Maliciously generated OAM messages could
also be used to bring down an otherwise healthy service (e.g., MPLS also be used to bring down an otherwise healthy service (e.g., MPLS
Pseudo Wire), and therefore affect service security. MPLS-ping does Pseudo Wire), and therefore affect service security. MPLS-ping does
not support authentication today, and that support should be not support authentication today, and that support should be
subject for future considerations. Bidirectional Forwarding subject for future considerations. Bidirectional Forwarding
Detection (BFD), however, does have support for carrying an Detection (BFD), however, does have support for carrying an
authentication object. It also supports Time-To-Live (TTL) authentication object. It also supports Time-To-Live (TTL)
processing as an anti-replay measure. Implementations conformant processing as an anti-replay measure. Implementations conformant
with this MPLS-ICI should support BFD authentication using MD5 and with this MPLS-ICI should support BFD authentication and must
must support the procedures for TTL processing. support the procedures for TTL processing.
8.1.2. Protection against DoS attacks in the Control 8.1.2. Protection Against DoS Attacks in the Control
Plane Plane
Implementation must have the ability to prevent signaling and Implementations must have the ability to prevent signaling and
routing DoS attacks on the control plane per interface and routing DoS attacks on the control plane per interface and
provider. Such prevention may be provided by rate-limiting provider. Such prevention may be provided by rate-limiting
signaling and routing messages that can be sent by a peer provider signaling and routing messages that can be sent by a peer provider
according to a traffic profile and by guarding against malformed according to a traffic profile and by guarding against malformed
packets. packets.
Equipment MUST provide the ability to filter signaling, routing, MPLS/GMPLS Security framework
and OAM packets destined for the device, and MUST provide the Equipment must provide the ability to filter signaling, routing,
ability to rate limit such packets. Packet filters SHOULD be and OAM packets destined for the device, and must provide the
capable of being separately applied per interface, and SHOULD have ability to rate limit such packets. Packet filters should be
capable of being separately applied per interface, and should have
minimal or no performance impact. For example, this allows an minimal or no performance impact. For example, this allows an
operator to filter or rate-limit signaling, routing, and OAM operator to filter or rate-limit signaling, routing, and OAM
messages that can be sent by a peer provider and limit such traffic messages that can be sent by a peer provider and limit such traffic
to a given profile. to a given profile.
MPLS/GMPLS Security framework
November 2008
During a control plane DoS attack against an ASBR, the router During a control plane DoS attack against an ASBR, the router
SHOULD guarantee sufficient resources to allow network operators to should guarantee sufficient resources to allow network operators to
execute network management commands to take corrective action, such execute network management commands to take corrective action, such
as turning on additional filters or disconnecting an interface as turning on additional filters or disconnecting an interface
under attack. DoS attacks on the control plane SHOULD NOT adversely under attack. DoS attacks on the control plane should not adversely
affect data plane performance. affect data plane performance.
Equipment running BGP MUST support the ability to limit the number
Equipment running BGP must support the ability to limit the number
of BGP routes received from any particular peer. Furthermore, in of BGP routes received from any particular peer. Furthermore, in
the case of IPVPN, a router MUST be able to limit the number of the case of IPVPN, a router must be able to limit the number of
routes learned from a BGP peer per IPVPN. In the case that a device routes learned from a BGP peer per IPVPN. In the case that a device
has multiple BGP peers, it SHOULD be possible for the limit to vary has multiple BGP peers, it should be possible for the limit to vary
between peers. between peers.
8.1.3. Protection against Malformed Packets 8.1.3. Protection against Malformed Packets
Equipment SHOULD be robust in the presence of malformed protocol Equipment should be robust in the presence of malformed protocol
packets. For example, malformed routing, signaling, and OAM packets packets. For example, malformed routing, signaling, and OAM packets
should be treated in accordance to the relevant protocol should be treated in accordance with the relevant protocol
specification. specification.
8.1.4. Ability to Enable/Disable Specific Protocols 8.1.4. Ability to Enable/Disable Specific Protocols
Ability to drop any signaling or routing protocol messages when Equipment must have the ability to drop any signaling or routing
these messages are to be processed by the ASBR but the protocol messages when these messages are to be processed by the
corresponding protocol is not enabled on that interface. ASBR but the corresponding protocol is not enabled on that
interface.
Equipment must allow an administrator to enable or disable a Equipment must allow an administrator to enable or disable a
protocol (default protocol is disabled unless administratively protocol (by default, the protocol is disabled unless
enable) on an interface basis. administratively enabled) on an interface basis.
Equipment MUST be able to drop any signaling or routing protocol Equipment must be able to drop any signaling or routing protocol
messages when these messages are to be processed by the ASBR but messages when these messages are to be processed by the ASBR but
the corresponding protocol is not enabled on that interface. This the corresponding protocol is not enabled on that interface. This
dropping SHOULD NOT adversely affect data plane or control plane dropping should not adversely affect data plane or control plane
performance. performance.
MPLS/GMPLS Security framework
8.1.5. Protection Against Incorrect Cross Connection 8.1.5. Protection Against Incorrect Cross Connection
The capability of detecting and locating faults in a LSP cross- The capability of detecting and locating faults in a LSP cross-
connect MUST be provided. Such faults may cause security violations connect must be provided. Such faults may cause security violations
as they result in directing traffic to the wrong destinations. This as they result in directing traffic to the wrong destinations. This
capability may rely on OAM functions. Equipment MUST support MPLS capability may rely on OAM functions. Equipment must support MPLS
LSP ping [RFC4379]. This MAY be used to verify end to end LSP ping [RFC4379]. This may be used to verify end-to-end
connectivity for the LSP (e.g., PW, TE Tunnel, VPN LSP, etc.), and connectivity for the LSP (e.g., PW, TE Tunnel, VPN LSP, etc.), and
to verify PE-to-PE connectivity for IP VPN services. to verify PE-to-PE connectivity for IP VPN services.
MPLS/GMPLS Security framework
November 2008
When routing information is advertised from one domain to the When routing information is advertised from one domain to the
other, operators must be able to guard against situations that other, operators must be able to guard against situations that
result in traffic hijacking, black-holing, resource stealing (e.g., result in traffic hijacking, black-holing, resource stealing (e.g.,
number of routes), etc. For instance, in the IPVPN case, an number of routes), etc. For instance, in the IPVPN case, an
operator must be able to block routes based on associated route operator must be able to block routes based on associated route
target attributes. In addition, mechanisms must exist to verify target attributes. In addition, mechanisms must exist to verify
whether a route advertised by a peer for a given VPN is actually a whether a route advertised by a peer for a given VPN is actually a
valid route and whether the VPN has a site attached or reachable valid route and whether the VPN has a site attached to or reachable
through that domain. through that domain.
Equipment (ASBRs and Route Reflectors (RRs)) supporting operation Equipment (ASBRs and Route Reflectors (RRs)) supporting operation
of BGP MUST be able to restrict which Route Target attributes are of BGP must be able to restrict which Route Target attributes are
sent to and accepted from a BGP peer across an ICI. Equipment sent to and accepted from a BGP peer across an ICI. Equipment
(ASBRs, RRs) SHOULD also be able to inform the peer regarding which (ASBRs, RRs) should also be able to inform the peer regarding which
Route Target attributes it will accept from a peer, because sending Route Target attributes it will accept from a peer, because sending
an incorrect Route Target can result in incorrect cross-connection an incorrect Route Target can result in incorrect cross-connection
of VPNs. Also, sending inappropriate route targets to a peer may of VPNs. Also, sending inappropriate route targets to a peer may
disclose confidential information. disclose confidential information.
8.1.6. Protection Against Spoofed Updates and Route 8.1.6. Protection Against Spoofed Updates and Route
Advertisements Advertisements
Equipment MUST support route filtering of routes received via a BGP Equipment must support route filtering of routes received via a BGP
peer sessions by applying policies that include one or more the peer session by applying policies that include one or more of the
following: AS path, BGP next hop, standard community or extended following: AS path, BGP next hop, standard community, or extended
community. community.
8.1.7. Protection of Confidential Information 8.1.7. Protection of Confidential Information
Ability to identify and block messages with confidential The ability to identify and block messages with confidential
information from leaving the trusted domain that can reveal information from leaving the trusted domain that can reveal
confidential information about network operation (e.g., performance confidential information about network operation (e.g., performance
OAM messages or MPLS-ping messages) is required. Service Providers OAM messages or MPLS-ping messages) is required. SPs must have the
must have the flexibility of handling these messages at the ASBR. flexibility of handling these messages at the ASBR.
Equipment SHOULD provide the ability to identify and restrict where Equipment should be able to identify and restrict where it sends
it sends messages or that can reveal confidential information about messages that can reveal confidential information about network
network operation (e.g., performance OAM messages, LSP Traceroute operation (e.g., performance OAM messages, LSP Traceroute
MPLS/GMPLS Security framework
messages). Service Providers must have the flexibility of handling messages). Service Providers must have the flexibility of handling
these messages at the ASBR. For example, equipment supporting LSP these messages at the ASBR. For example, equipment supporting LSP
Traceroute MAY limit to which addresses replies can be sent. Traceroute may limit to which addresses replies can be sent.
Note: This capability should be used with care. For example, if a Note: This capability should be used with care. For example, if a
service provider chooses to prohibit the exchange of LSP ping SP chooses to prohibit the exchange of LSP ping messages at the
messages at the ICI, it may make it more difficult to debug ICI, it may make it more difficult to debug incorrect cross-
incorrect cross-connection of LSPs or other problems. connection of LSPs or other problems.
A provider may decide to progress these messages if they are A SP may decide to progress these messages if they arrive from a
incoming from a trusted provider and are targeted to specific trusted provider and are targeted to specific, agreed-on addresses.
agreed-on addresses. Another provider may decide to traffic police, Another provider may decide to traffic police, reject, or apply
MPLS/GMPLS Security framework other policies to these messages. Solutions must enable providers
November 2008 to control the information that is relayed to another provider
about the path that a LSP takes. For example, when using the RSVP-
reject, or apply policies to these messages. Solutions must enable TE record route object or MPLS-ping trace, a provider must be able
providers to control the information that is relayed to another to control the information contained in corresponding messages when
provider about the path that a LSP takes. For example, in RSVP-TE
record route object or MPLS-ping trace, a provider must be able to
control the information contained in corresponding messages when
sent to another provider. sent to another provider.
8.1.8. Protection Against over-provisioned number of 8.1.8. Protection Against Over-provisioned Number of
RSVP-TE LSPs and bandwidth reservation RSVP-TE LSPs and Bandwidth Reservation
In addition to the control plane protection mechanisms listed in In addition to the control plane protection mechanisms listed in
the previous section on Control plane protection with RSVP-TE, the the previous section on Control plane protection with RSVP-TE, the
ASBR must be able both to limit the number of LSPs that can be set ASBR must be able both to limit the number of LSPs that can be set
up by other domains and to limit the amount of bandwidth that can up by other domains and to limit the amount of bandwidth that can
be reserved. A provider's ASBR may deny a LSP set up request or a be reserved. A provider's ASBR may deny a LSP set up request or a
bandwidth reservation request sent by another provider's whose the bandwidth reservation request sent by another provider's whose the
limits have been reached. limits have been reached.
8.2. Data Plane Protection 8.2. Data Plane Protection
8.2.1. Protection against DoS in the Data Plane 8.2.1. Protection against DoS in the Data Plane
This is described earlier in this document.
8.2.2. Protection against Label Spoofing This is described in Section 5 of this document.
Verification that a label received across an interconnect was 8.2.2. Protection Against Label Spoofing
actually assigned to the provider across the interconnect. If the
label was not assigned to the provider, the packet MUST be dropped.
Equipment MUST be able to verify that a label received across an Equipment must be able to verify that a label received across an
interconnect was actually assigned to a LSP arriving from the interconnect was actually assigned to a LSP arriving across that
provider across that interconnect. If the label was not assigned to interconnect. If a label not assigned to a LSP arrives at this
a LSP which arrives at this router from the correct neighboring router from the correct neighboring provider, the packet must be
provider, the packet MUST be dropped. This verification can be dropped. This verification can be applied to the top label only.
applied to the top label only. The top label is the received top The top label is the received top label and every label that is
label and every label that is exposed by label popping to be used exposed by label popping to be used for forwarding decisions.
for forwarding decisions.
Equipment MUST provide the capability of dropping MPLS-labeled Equipment must provide the capability of dropping MPLS-labeled
packets if all labels in the stack are not processed. This lets packets if all labels in the stack are not processed. This lets
carriers guarantee that every label that enters its domain from SPs guarantee that every label that enters its domain from another
another carrier was actually assigned to that carrier. carrier was actually assigned to that carrier.
MPLS/GMPLS Security framework
The following requirements are not directly reflected in this The following requirements are not directly reflected in this
document but must be used as guidance for addressing further work. document but must be used as guidance for addressing further work.
Solutions MUST NOT force operators to reveal reachability Solutions must NOT force operators to reveal reachability
information to routers within their domains. <note: It is believed information to routers within their domains. <note: It is believed
MPLS/GMPLS Security framework
November 2008
that this requirement is met via other requirements specified in that this requirement is met via other requirements specified in
this section plus the normal operation of IP routing, which does this section plus the normal operation of IP routing, which does
not reveal individual hosts.> not reveal individual hosts.>
Mechanisms to authenticate and validate a dynamic setup request Mechanisms to authenticate and validate a dynamic setup request
MUST be available. For instance, if dynamic signaling of a TE-LSP must be available. For instance, if dynamic signaling of a TE-LSP
or PW is crossing a domain boundary, there must be a way to detect or PW is crossing a domain boundary, there must be a way to detect
whether the LSP source is who it claims to be and that he is whether the LSP source is who it claims to be and that it is
allowed to connect to the destination. allowed to connect to the destination.
8.2.3. Protection using ingress traffic policing and 8.2.3. Protection Using Ingress Traffic Policing and
enforcement Enforcement
The following simple diagram illustrates a potential security issue The following simple diagram illustrates a potential security issue
on the data plane issue across a MPLS interconnect: on the data plane across a MPLS interconnect:
SP2 - ASBR2 - labeled path - ASBR1 - P1 - SP1's PSN - P2 - PE1 SP2 - ASBR2 - labeled path - ASBR1 - P1 - SP1's PSN - P2 - PE1
| | | | | | | |
|< AS2 >|<MPLS interconnect>|< AS1 >| |< AS2 >|<MPLS interconnect>|< AS1 >|
Traffic flow direction is from SP2 to SP1 Traffic flow direction is from SP2 to SP1
In the case of down stream label assignment, the transit label used In the case of down stream label assignment, the transit label used
by ASBR2 is allocated by ASBR1, which in turn advertises it to by ASBR2 is allocated by ASBR1, which in turn advertises it to
ASB2 (downstream unsolicited or on-demand), and this label is used ASB2 (downstream unsolicited or on-demand), this label is used for
for a service context (VPN label, PW VC label, etc.), and this LSP a service context (VPN label, PW VC label, etc.), and this LSP is
is normally terminated at a forwarding table belonging to the normally terminated at a forwarding table belonging to the service
service instance on PE (PE1) in SP1. instance on PE (PE1) in SP1.
In the example above, ASBR1 would not know whether the label of an In the example above, ASBR1 would not know whether the label of an
incoming packet from ASBR2 over the interconnect is a VPN label or incoming packet from ASBR2 over the interconnect is a VPN label or
PSN label for AS1. So it is possible (though rare) that ASBR2 can PSN label for AS1. So it is possible (though unlikely) that ASBR2
be accidentally or intentionally configured such that the incoming can be accidentally or intentionally configured such that the
label could match a PSN label (e.g., LDP) in AS1. Then, this LSP incoming label could match a PSN label (e.g., LDP) in AS1. Then,
would end up on the global plane of an infrastructure router (P or this LSP would end up on the global plane of an infrastructure
PE1), and this could invite a unidirectional attack on that P or router (P or PE1), and this could invite a unidirectional attack on
PE1 where the LSP terminates. that P or PE1 where the LSP terminates.
To mitigate this threat, implementations SHOULD be able to do a To mitigate this threat, implementations should be able to do a
forwarding path look-up for the label on an incoming packet from an forwarding path look-up for the label on an incoming packet from an
interconnect in a Label Forwarding Information Base (LFIB) space interconnect in a Label Forwarding Information Base (LFIB) space
that is only intended for its own service context or provide a that is only intended for its own service context or provide a
MPLS/GMPLS Security framework
mechanism on the data plane that would ensure the incoming labels mechanism on the data plane that would ensure the incoming labels
are what ASBR1 has allocated and advertised. are what ASBR1 has allocated and advertised.
A similar concept has been proposed in "Requirements for Multi- A similar concept has been proposed in "Requirements for Multi-
Segment Pseudowire Emulation Edge-to-Edge (PWE3)" [RFC5254]. Segment Pseudowire Emulation Edge-to-Edge (PWE3)" [RFC5254].
MPLS/GMPLS Security framework
November 2008
When using upstream label assignment, the upstream source must be When using upstream label assignment, the upstream source must be
identified and authenticated so the labels can be accepted as from identified and authenticated so the labels can be accepted as from a
trusted source. trusted source.
9. Summary of MPLS and GMPLS Security 9. Summary of MPLS and GMPLS Security
The following summary provides a quick check list of MPLS and GMPLS The following summary provides a quick check list of MPLS and GMPLS
security threats, defense techniques, and the best practice guide security threats, defense techniques, and the best practice guide
outlines for MPLS and GMPLS deployment. outlines for MPLS and GMPLS deployment.
9.1. MPLS and GMPLS Specific Security Threats 9.1. MPLS and GMPLS Specific Security Threats
9.1.1. Control plane attacks 9.1.1. Control Plane Attacks
Types of attacks on the control plane: Types of attacks on the control plane:
- Unauthorized LSP creation - Unauthorized LSP creation
- LSP message interception - LSP message interception
Attacks against RSVP-TE: DoS attack with setting up Attacks against RSVP-TE: DoS attack with setting up
unauthorized LSP and/or LSP messages. unauthorized LSP and/or LSP messages.
Attacks against LDP: DoS attack with storms of LDP Hello Attacks against LDP: DoS attack with storms of LDP Hello
messages or LDP TCP Syn messages. messages or LDP TCP SYN messages.
Attacks may be launched from external or internal sources, or Attacks may be launched from external or internal sources, or
through SP management systems. through a SP's management systems.
Attacks may be targeted to the SP routing protocols or Attacks may be targeted at the SP's routing protocols or
infrastructure elements. infrastructure elements.
In general, control protocols may be attacked by: In general, control protocols may be attacked by:
- MPLS signaling (LDP, RSVP-TE) - MPLS signaling (LDP, RSVP-TE)
- PCE signaling - PCE signaling
- IPsec signaling (IKE and IKEv2) - IPsec signaling (IKE and IKEv2)
- ICMP and ICMPv6 - ICMP and ICMPv6
- L2TP - L2TP
- BGP-based membership discovery - BGP-based membership discovery
- Database-based membership discovery (e.g., RADIUS) - Database-based membership discovery (e.g., RADIUS)
- OAM and diagnostic protocol such as MPLS-ping and LMP - OAM and diagnostic protocols such as MPLS-ping and LMP
MPLS/GMPLS Security framework
- Other protocols that may be important to the control - Other protocols that may be important to the control
infrastructure, e.g., DNS, LMP, NTP, SNMP, and GRE. infrastructure, e.g., DNS, LMP, NTP, SNMP, and GRE.
9.1.2. Data plane attacks 9.1.2. Data Plane Attacks
- Unauthorized observation of data traffic - Unauthorized observation of data traffic
MPLS/GMPLS Security framework
November 2008
- Data traffic modification - Data traffic modification
- Spoofing and replay - Spoofing and replay
- Unauthorized Deletion - Unauthorized Deletion
- Unauthorized Traffic Pattern Analysis - Unauthorized Traffic Pattern Analysis
- Denial of Service Attacks - Denial of Service
9.2. Defense Techniques 9.2. Defense Techniques
1) Authentication: 1) Authentication:
- Identity authentication - Key management - Bi-directional authentication
- Key management
- Management System Authentication - Management System Authentication
- Peer-to-peer authentication - Peer-to-peer authentication
2) Cryptographic techniques 2) Cryptographic techniques
3) Use of IPsec in MPLS/GMPLS networks 3) Use of IPsec in MPLS/GMPLS networks
4) Encryption for device configuration and management 4) Encryption for device configuration and management
5) Cryptographic Techniques for MPLS Pseudowires 5) Cryptographic Techniques for MPLS Pseudowires
6) End-to-End versus Hop-by-Hop Protection (CE-CE, PE-PE, PE-CE) 6) End-to-End versus Hop-by-Hop Protection (CE-CE, PE-PE, PE-CE)
7) Access Control techniques 7) Access Control techniques
- Filtering - Filtering
- Firewalls - Firewalls
- Access Control to management interfaces - Access Control to management interfaces
8) Infrastructure isolation 8) Infrastructure isolation
9) Use of aggregation infrastructure 9) Use of aggregated infrastructure
10) Quality Control Processes 10) Quality Control Processes
11) Testable MPLS/GMPLS Service 11) Testable MPLS/GMPLS Service
12) End-to-end connectivity verification techniques 12) End-to-end connectivity verification
13) Hop-by-hop resource configuration verification and discovery 13) Hop-by-hop resource configuration verification and discovery
techniques
9.3. Service Provider MPLS and GMPLS Best Practice Outlines 9.3. Service Provider MPLS and GMPLS Best Practice Outlines
9.3.1. SP infrastructure protection 9.3.1. SP Infrastructure Protection
1) General control plane protection 1) General control plane protection
- Protocol authentication within the core - Protocol authentication within the core
- Infrastructure Hiding (e.g. disable TTL propagation) - Infrastructure hiding (e.g. disable TTL propagation)
MPLS/GMPLS Security framework
2) RSVP control plane protection 2) RSVP control plane protection
- Using RSVP security tools - RSVP security tools
- Isolation of the trusted domain - Isolation of the trusted domain
- Deactivating RSVP on interfaces with neighbors who are not - Deactivating RSVP on interfaces with neighbors who are not
authorized to use RSVP authorized to use RSVP
- RSVP neighbor filtering at the protocol level and data plane - RSVP neighbor filtering at the protocol level and data plane
level level
MPLS/GMPLS Security framework
November 2008
- Authentication for RSVP messages - Authentication for RSVP messages
- RSVP message pacing - RSVP message pacing
3) LDP control plane protection (similar techniques as for RSVP) 3) LDP control plane protection (similar techniques as for RSVP)
4) Data plane protection 4) Data plane protection
- User Access link protection - User access link protection
- Link Authentication - Link authentication
- Access routing control (e.g. prefix limits, route dampening, - Access routing control (e.g., prefix limits, route
routing table limits (e.g. VRF limits) dampening, routing table limits (such as VRF limits)
- Access QoS control - Access QoS control
- Using customer service monitoring tools - Customer service monitoring tools
- Use of MPLS-ping (with its own control plane security) to - Use of MPLS-ping (with its own control plane security) to
verify end-to-end connectivity of MPLS LSPs verify end-to-end connectivity of MPLS LSPs
- LMP (with its own security) to verify hop-by-hop - LMP (with its own security) to verify hop-by-hop
connectivity connectivity.
9.3.2. Inter-provider Security 9.3.2. Inter-provider Security
Inter-provider connections are high security risk areas. Similar Inter-provider connections are high security risk areas. Similar
techniques and procedures as described in for SP general core techniques and procedures as described for SP's general core
protection are listed below for inter-provider connections. protection are listed below for Inter-provider connections.
1) Control plane protection at the inter-provider connections 1) Control plane protection at Inter-provider connections
- Authentication of Signaling Sessions - Authentication of signaling sessions
- Protection against DoS attacks in the Control Plane - Protection against DoS attacks in the control plane
- Protection against Malformed Packets - Protection against malformed packets
- Ability to Enable/Disable Specific Protocols - Ability to enable/disable specific protocols
- Protection Against Incorrect Cross Connection - Protection against incorrect cross connection
- Protection Against Spoofed Updates and Route Advertisements - Protection against spoofed updates and route advertisements
- Protection of Confidential Information - Protection of confidential information
- Protection Against over-provisioned number of RSVP-TE LSPs - Protection against over-provisioned number of RSVP-TE LSPs
and bandwidth reservation and bandwidth reservation
2) Data Plane Protection at the inter-provider connections 2) Data Plane Protection at the inter-provider connections
- Protection against DoS in the Data Plane - Protection against DoS in the data plane
- Protection against Label Spoofing - Protection against label spoofing
10. Security Considerations 10. Security Considerations
MPLS/GMPLS Security framework
Security considerations constitute the sole subject of this memo Security considerations constitute the sole subject of this memo
and hence are discussed throughout. Here we recap what has been and hence are discussed throughout. Here we recap what has been
presented and explain at a high level the role of each type of presented and explain at a high level the role of each type of
consideration in an overall secure MPLS/GMPLS system. consideration in an overall secure MPLS/GMPLS system.
The document describes a number of potential security threats. The document describes a number of potential security threats.
Some of these threats have already been observed occurring in Some of these threats have already been observed occurring in
running networks; others are largely theoretical at this time. running networks; others are largely hypothetical at this time.
MPLS/GMPLS Security framework
November 2008
DoS attacks and intrusion attacks from the Internet against service DoS attacks and intrusion attacks from the Internet against SPs'
providers' infrastructure have been seen. DoS "attacks" (typically infrastructure have been seen. DoS "attacks" (typically not
not malicious) have also been seen in which CE equipment overwhelms malicious) have also been seen in which CE equipment overwhelms PE
PE equipment with high quantities or rates of packet traffic or equipment with high quantities or rates of packet traffic or
routing information. Operational or provisioning errors are cited routing information. Operational or provisioning errors are cited
by service providers as one of their prime concerns. by SPs as one of their prime concerns.
The document describes a variety of defensive techniques that may The document describes a variety of defensive techniques that may
be used to counter the suspected threats. All of the techniques be used to counter the suspected threats. All of the techniques
presented involve mature and widely implemented technologies that presented involve mature and widely implemented technologies that
are practical to implement. are practical to implement.
The document describes the importance of detecting, monitoring, and The document describes the importance of detecting, monitoring, and
reporting attacks, both successful and unsuccessful. These reporting attacks, both successful and unsuccessful. These
activities are essential for "understanding one's enemy", activities are essential for "understanding one's enemy",
mobilizing new defenses, and obtaining metrics about how secure the mobilizing new defenses, and obtaining metrics about how secure the
skipping to change at page 52, line 37 skipping to change at page 53, line 43
The document evaluates MPLS/GMPLS security requirements from a The document evaluates MPLS/GMPLS security requirements from a
customer's perspective as well as from a service provider's customer's perspective as well as from a service provider's
perspective. These sections re-evaluate the identified threats perspective. These sections re-evaluate the identified threats
from the perspectives of the various stakeholders and are meant to from the perspectives of the various stakeholders and are meant to
assist equipment vendors and service providers, who must ultimately assist equipment vendors and service providers, who must ultimately
decide what threats to protect against in any given configuration decide what threats to protect against in any given configuration
or service offering. or service offering.
11. IANA Considerations 11. IANA Considerations
No new IANA considerations. This document contains no new IANA considerations.
12. Normative References 12. Normative References
[RFC2747] F. Baker, et al., "RSVP Cryptographic Authentication", [RFC2747] F. Baker, et al., "RSVP Cryptographic Authentication",
EFC 2741, January 2000. EFC 2741, January 2000.
MPLS/GMPLS Security framework
[RFC3031] E. Rosen, A. Viswanathan, R. Callon, "Multiprotocol Label [RFC3031] E. Rosen, A. Viswanathan, R. Callon, "Multiprotocol Label
Switching Architecture", RFC 3031, January 2001. Switching Architecture", RFC 3031, January 2001.
[RFC3097] R. Braden and L. Zhang, "RSVP Cryptographic [RFC3097] R. Braden and L. Zhang, "RSVP Cryptographic
Authentication - Updated Message Type Value", RFC 3097, April 2001. Authentication - Updated Message Type Value", RFC 3097, April 2001.
[RFC3209] Awduche, et al., "RSVP-TE: Extensions to RSVP for LSP
Tunnels", December 2001.
[RFC3945] E. Mannie, "Generalized Multi-Protocol Label Switching [RFC3945] E. Mannie, "Generalized Multi-Protocol Label Switching
(GMPLS) Architecture", RFC 3945, October 2004. (GMPLS) Architecture", RFC 3945, October 2004.
MPLS/GMPLS Security framework [RFC4106] J. Viega, D. McGrew, "The Use of Galois/Counter Mode
November 2008 (GCM) in IPsec Encapsulating Security Payload (ESP)", June 2005.
[RFC3209] Awduche, et al., "RSVP-TE: Extensions to RSVP for LSP
Tunnels", December 2001.
[RFC4301] S. Kent, K. Seo, "Security Architecture for the Internet [RFC4301] S. Kent, K. Seo, "Security Architecture for the Internet
Protocol," December 2005. Protocol," December 2005.
[RFC4302] S. Kent, "IP Authentication Header," December 2005. [RFC4302] S. Kent, "IP Authentication Header," December 2005.
[RFC4835] V. Manral, "Cryptographic Algorithm Implementation
Requirements for Encapsulating Security Payload (ESP) and
Authentication Header (AH)", April 2007.
[RFC4306] C. Kaufman, "Internet Key Exchange (IKEv2) [RFC4306] C. Kaufman, "Internet Key Exchange (IKEv2)
Protocol",December 2005. Protocol",December 2005.
[RFC4309] Housley, R., "Using Advanced Encryption Standard (AES) [RFC4309] Housley, R., "Using Advanced Encryption Standard (AES)
CCM Mode with IPsec Encapsulating Security Payload (ESP)", December CCM Mode with IPsec Encapsulating Security Payload (ESP)", December
2005. 2005.
[RFC5246] T. Dierks and E. Rescorla, "The Transport Layer Security
(TLS) Protocol, Version 1.2," August 2008.
[RFC4379] K. Kompella and G. Swallow, "Detecting Multi-Protocol [RFC4379] K. Kompella and G. Swallow, "Detecting Multi-Protocol
Label Switched (MPLS) Data Plane Failures", February 2006. Label Switched (MPLS) Data Plane Failures", February 2006.
[RFC4447] Martini, et al., "Pseudowire Setup and Maintenance Using [RFC4447] Martini, et al., "Pseudowire Setup and Maintenance Using
the Label Distribution Protocol (LDP)", April 2006. the Label Distribution Protocol (LDP)", April 2006.
[RFC4835] V. Manral, "Cryptographic Algorithm Implementation
Requirements for Encapsulating Security Payload (ESP) and
Authentication Header (AH)", April 2007.
[RFC5246] T. Dierks and E. Rescorla, "The Transport Layer Security
(TLS) Protocol, Version 1.2," August 2008.
[RFC5036] Andersson, et al., "LDP Specification", October 2007. [RFC5036] Andersson, et al., "LDP Specification", October 2007.
[STD62] "Simple Network Management Protocol, Version 3,", December [STD62] "Simple Network Management Protocol, Version 3,", December
2002. 2002.
[STD-8] J. Postel and J. Reynolds, "TELNET Protocol Specification", [STD-8] J. Postel and J. Reynolds, "TELNET Protocol Specification",
STD 8, May 1983. STD 8, May 1983.
13. Informational References MPLS/GMPLS Security framework
13. Informative References
[RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC 2119] Bradner, S., "Key words for use in RFCs to Indicate
[OIF-SMI-01.0] Renee Esposito, "Security for Management Interfaces [OIF-SMI-01.0] Renee Esposito, "Security for Management Interfaces
to Network Elements", Optical Internetworking Forum, Sept. 2003. to Network Elements", Optical Internetworking Forum, Sept. 2003.
MPLS/GMPLS Security framework
November 2008
[OIF-SMI-02.1] Renee Esposito, "Addendum to the Security for [OIF-SMI-02.1] Renee Esposito, "Addendum to the Security for
Management Interfaces to Network Elements", Optical Internetworking Management Interfaces to Network Elements", Optical Internetworking
Forum, March 2006. Forum, March 2006.
[RFC2104] H. Krawczyk, M. Bellare, R. Canetti, "HMAC: Keyed-Hashing [RFC2104] H. Krawczyk, M. Bellare, R. Canetti, "HMAC: Keyed-Hashing
for Message Authentication," February 1997. for Message Authentication," February 1997.
[RFC2411] R. Thayer, N. Doraswamy, R. Glenn, "IP Security Document [RFC2411] R. Thayer, N. Doraswamy, R. Glenn, "IP Security Document
Roadmap," November 1998. Roadmap," November 1998.
skipping to change at page 54, line 45 skipping to change at page 56, line 5
[RFC4110] R. Callon and M. Suzuki, "A Framework for Layer 3 [RFC4110] R. Callon and M. Suzuki, "A Framework for Layer 3
Provider-Provisioned Virtual Private Networks (PPVPNs)", July 2005. Provider-Provisioned Virtual Private Networks (PPVPNs)", July 2005.
[RFC4111] L. Fang, "Security Framework of Provider Provisioned [RFC4111] L. Fang, "Security Framework of Provider Provisioned
VPN", RFC 4111, July 2005. VPN", RFC 4111, July 2005.
[RFC4230] H. Tschofenig and R. Graveman, "RSVP Security [RFC4230] H. Tschofenig and R. Graveman, "RSVP Security
Properties", December 2005. Properties", December 2005.
MPLS/GMPLS Security framework
[RFC4308] P. Hoffman, "Cryptographic Suites for IPsec", December [RFC4308] P. Hoffman, "Cryptographic Suites for IPsec", December
2005. 2005.
[RFC4593] A. Barbir, S. Murphy, Y. Yang, "Generic Threats to Routing [RFC4593] A. Barbir, S. Murphy, Y. Yang, "Generic Threats to Routing
Protocols", October 2006. Protocols", October 2006.
[RFC4808] S. Bellovin, "Key Change Strategies for TCP-MD5", March [RFC4808] S. Bellovin, "Key Change Strategies for TCP-MD5", March
2007. 2007.
[RFC4864] G. Van de Velde, T. Hain, R. Droms, "Local Network
Protection for IPv6", May 2007.
[RFC4869] L. Law and J. Solinas, "Suite B Cryptographic Suites for [RFC4869] L. Law and J. Solinas, "Suite B Cryptographic Suites for
IPsec", April 2007. IPsec", April 2007.
MPLS/GMPLS Security framework
November 2008
[RFC5254] N. Bitar, M. Bocci, L. Martini, "Requirements for Multi- [RFC5254] N. Bitar, M. Bocci, L. Martini, "Requirements for Multi-
Segment Pseudowire Emulation Edge-to-Edge (PWE3)", October 2008. Segment Pseudowire Emulation Edge-to-Edge (PWE3)", October 2008.
[MFA MPLS ICI] N. Bitar, "MPLS InterCarrier Interconnect Technical [MFA MPLS ICI] N. Bitar, "MPLS InterCarrier Interconnect Technical
Specification", IP/MPLS Forum 19.0.0, April 2008. Specification", IP/MPLS Forum 19.0.0, April 2008.
[opsec efforts] C. Lonvick and D. Spak, "Security Best Practices [opsec efforts] C. Lonvick and D. Spak, "Security Best Practices
Efforts and Documents", draft-ietf-opsec-efforts-08.txt, June 2008. Efforts and Documents", draft-ietf-opsec-efforts-08.txt, June 2008.
[RSVP-key] M. Behringer, F. Le Faucheur, "Applicability of Keying [RSVP-key] M. Behringer, F. Le Faucheur, "Applicability of Keying
Methods for RSVP Security", draft-ietf-tsvwg-rsvp-security- Methods for RSVP Security", draft-ietf-tsvwg-rsvp-security-
groupkeying-03.txt, March 2009.
14. Author's Addresses 14. Author's Addresses
Luyuan Fang Luyuan Fang
Cisco Systems, Inc. Cisco Systems, Inc.
300 Beaver Brook Road 300 Beaver Brook Road
Boxborough, MA 01719 Boxborough, MA 01719
USA USA
Email: lufang@cisco.com Email: lufang@cisco.com
Michael Behringer Michael Behringer
Cisco Systems, Inc. Cisco Systems, Inc.
Village d'Entreprises Green Side Village d'Entreprises Green Side
400, Avenue Roumanille, Batiment T 3 400, Avenue Roumanille, Batiment T 3
06410 Biot, Sophia Antipolis 06410 Biot, Sophia Antipolis
FRANCE FRANCE
Email: mbehring@cisco.com Email: mbehring@cisco.com
MPLS/GMPLS Security framework
Ross Callon Ross Callon
Juniper Networks Juniper Networks
10 Technology Park Drive 10 Technology Park Drive
Westford, MA 01886 Westford, MA 01886
USA USA
Email: rcallon@juniper.net Email: rcallon@juniper.net
Richard Graveman
RFG Security
15 Park Avenue
Morristown, NJ 07960
Email: rfg@acm.org
Jean-Louis Le Roux Jean-Louis Le Roux
France Telecom France Telecom
2, avenue Pierre-Marzin 2, avenue Pierre-Marzin
22307 Lannion Cedex 22307 Lannion Cedex
FRANCE FRANCE
MPLS/GMPLS Security framework
November 2008
Email: jeanlouis.leroux@francetelecom.com Email: jeanlouis.leroux@francetelecom.com
Raymond Zhang Raymond Zhang
British Telecom British Telecom
2160 E. Grand Ave. El Segundo, CA 90025 BT Center
USA 81 Newgate Street
London, EC1A 7AJ
United Kingdom
Email: raymond.zhang@bt.com Email: raymond.zhang@bt.com
Paul Knight Paul Knight
Nortel 39 N. Hancock St.
600 Technology Park Drive Lexington, MA 02420
Billerica, MA 01821
Email: paul.knight@nortel.com Email: paul.the.knight@gmail.com
Yaakov (Jonathan) Stein Yaakov (Jonathan) Stein
RAD Data Communications RAD Data Communications
24 Raoul Wallenberg St., Bldg C 24 Raoul Wallenberg St., Bldg C
Tel Aviv 69719 Tel Aviv 69719
ISRAEL ISRAEL
Email: yaakov_s@rad.com Email: yaakov_s@rad.com
MPLS/GMPLS Security framework
Nabil Bitar Nabil Bitar
Verizon Verizon
40 Sylvan Road 40 Sylvan Road
Waltham, MA 02145 Waltham, MA 02145
Email: nabil.bitar@verizon.com Email: nabil.bitar@verizon.com
Richard Graveman
RFG Security
15 Park Avenue
Morristown, NJ 07960
Email: rfg@acm.org
Monique Morrow Monique Morrow
Glatt-com Glatt-com
CH-8301 Glattzentrum CH-8301 Glattzentrum
Switzerland Switzerland
Email: mmorrow@cisco.com Email: mmorrow@cisco.com
Adrian Farrel Adrian Farrel
Old Dog Consulting Old Dog Consulting
Email: adrian@olddog.co.uk Email: adrian@olddog.co.uk
MPLS/GMPLS Security framework
November 2008
Full Copyright Statement
Copyright (C) The IETF Trust (2008).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on
an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE
REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE
IETF TRUST AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL
WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY
WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE
ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR PURPOSE.
Intellectual Property
The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed
to pertain to the implementation or use of the technology described
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rights might or might not be available; nor does it represent that
it has made any independent effort to identify any such rights.
Information on the procedures with respect to rights in RFC
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Copies of IPR disclosures made to the IETF Secretariat and any
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The IETF invites any interested party to bring to its attention any
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rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at ietf-
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15. Acknowledgements 15. Acknowledgements
Funding for the RFC Editor function is provided by the IETF Funding for the RFC Editor function is provided by the IETF
Administrative Support Activity (IASA). Administrative Support Activity (IASA).
MPLS/GMPLS Security framework
November 2008
The authors and contributors would also like to acknowledge the The authors and contributors would also like to acknowledge the
helpful comments and suggestions from Sam Hartman, Dimitri helpful comments and suggestions from Sam Hartman, Dimitri
Papadimitriou, Kannan Varadhan, Stephen Farrell, and Scott Brim in Papadimitriou, Kannan Varadhan, Stephen Farrell, and Scott Brim in
particular for his comments and discussion through GEN-ART review. particular for his comments and discussion through GEN-ART review.
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