draft-ietf-idr-rfc5575bis-04.txt   draft-ietf-idr-rfc5575bis-05.txt 
IDR Working Group S. Hares IDR Working Group S. Hares
Internet-Draft Huawei Internet-Draft Huawei
Obsoletes: 5575,7674 (if approved) C. Loibl Obsoletes: 5575,7674 (if approved) C. Loibl
Intended status: Standards Track Next Layer Communications Intended status: Standards Track Next Layer Communications
Expires: January 3, 2018 R. Raszuk Expires: April 22, 2018 R. Raszuk
Bloomberg LP Bloomberg LP
D. McPherson D. McPherson
Verisign Verisign
M. Bacher M. Bacher
T-Mobile Austria T-Mobile Austria
July 2, 2017 October 19, 2017
Dissemination of Flow Specification Rules Dissemination of Flow Specification Rules
draft-ietf-idr-rfc5575bis-04 draft-ietf-idr-rfc5575bis-05
Abstract Abstract
This document updates RFC5575 which defines a Border Gateway Protocol This document updates [RFC5575] which defines a Border Gateway
Network Layer Reachability Information (BGP NLRI) encoding format Protocol Network Layer Reachability Information (BGP NLRI) encoding
that can be used to distribute traffic flow specifications. This format that can be used to distribute traffic Flow Specifications.
allows the routing system to propagate information regarding more This allows the routing system to propagate information regarding
specific components of the traffic aggregate defined by an IP more specific components of the traffic aggregate defined by an IP
destination prefix. This draft specifies IPv4 traffic flow destination prefix.
specifications via a BGP NLRI which carries traffic flow
specification filter, and an Extended community value which encodes
actions a routing system can take if the packet matches the traffic
flow filters. The flow filters and the actions are processed in a
fixed order. Other drafts specify IPv6, MPLS addresses, L2VPN
addresses, and NV03 encapsulation of IP addresses.
This document updates RFC5575 to correct unclear specifications in It specifies IPv4 traffic Flow Specifications via a BGP NLRI which
carries traffic Flow Specification filter, and an Extended community
value which encodes actions a routing system can take if the packet
matches the traffic flow filters. The flow filters and the actions
are processed in a fixed order. Other drafts specify IPv6, MPLS
addresses, L2VPN addresses, and NV03 encapsulation of IP addresses.
This document updates [RFC5575] to correct unclear specifications in
the flow filters and to provide rules for actions which interfere the flow filters and to provide rules for actions which interfere
(e.g. redirection of traffic and flow filtering). (e.g. redirection of traffic and flow filtering).
Applications which use the bgp flow specification are: 1) application Applications which use the bgp Flow Specification are: 1) application
which automate of inter-domain coordination of traffic filtering, which automate inter-domain coordination of traffic filtering, such
such as what is required in order to mitigate (distributed) denial- as what is required in order to mitigate (distributed) denial-of-
of-service attacks; 2) application which control traffic filtering in service attacks; 2) applications which control traffic filtering in
the context of a BGP/MPLS VPN service, and 3) applications with the context of a BGP/MPLS VPN service, and 3) applications with
centralized control of traffic in a SDN or NFV context. Some of centralized control of traffic in a SDN or NFV context. Some
deployments of these three applications can be handled by the strict deployments of these three applications can be handled by the strict
ordering of the BGP NLRI traffic flow filters, and the strict actions ordering of the BGP NLRI traffic flow filters, and the strict actions
encoded in the Extended Community Flow Specification actions. encoded in the extended community Flow Specification actions.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on January 3, 2018. This Internet-Draft will expire on April 22, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
skipping to change at page 3, line 13 skipping to change at page 3, line 13
4.2.8. Type 8 - ICMP code . . . . . . . . . . . . . . . . . 11 4.2.8. Type 8 - ICMP code . . . . . . . . . . . . . . . . . 11
4.2.9. Type 9 - TCP flags . . . . . . . . . . . . . . . . . 11 4.2.9. Type 9 - TCP flags . . . . . . . . . . . . . . . . . 11
4.2.10. Type 10 - Packet length . . . . . . . . . . . . . . . 12 4.2.10. Type 10 - Packet length . . . . . . . . . . . . . . . 12
4.2.11. Type 11 - DSCP (Diffserv Code Point) . . . . . . . . 12 4.2.11. Type 11 - DSCP (Diffserv Code Point) . . . . . . . . 12
4.2.12. Type 12 - Fragment . . . . . . . . . . . . . . . . . 12 4.2.12. Type 12 - Fragment . . . . . . . . . . . . . . . . . 12
4.3. Examples of Encodings . . . . . . . . . . . . . . . . . . 12 4.3. Examples of Encodings . . . . . . . . . . . . . . . . . . 12
5. Traffic Filtering . . . . . . . . . . . . . . . . . . . . . . 13 5. Traffic Filtering . . . . . . . . . . . . . . . . . . . . . . 13
5.1. Ordering of Traffic Filtering Rules . . . . . . . . . . . 14 5.1. Ordering of Traffic Filtering Rules . . . . . . . . . . . 14
6. Validation Procedure . . . . . . . . . . . . . . . . . . . . 16 6. Validation Procedure . . . . . . . . . . . . . . . . . . . . 16
7. Traffic Filtering Actions . . . . . . . . . . . . . . . . . . 17 7. Traffic Filtering Actions . . . . . . . . . . . . . . . . . . 17
7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 18 7.1. Traffic Rate in Bytes (traffic-rate-bytes) sub-type 0x06 19
7.2. Traffic Rate in Packets (traffic-rate-packets) sub-type 7.2. Traffic Rate in Packets (traffic-rate-packets) sub-type
TBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 TBD . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
7.3. Traffic-action (traffic-action) sub-type 0x07 . . . . . . 19 7.3. Traffic-action (traffic-action) sub-type 0x07 . . . . . . 19
7.4. RT Redirect (rt-redirect) sub-type 0x08 . . . . . . . . . 20 7.4. RT Redirect (rt-redirect) sub-type 0x08 . . . . . . . . . 20
7.5. Traffic Marking (traffic-marking) sub-type 0x09 . . . . . 20 7.5. Traffic Marking (traffic-marking) sub-type 0x09 . . . . . 20
7.6. Rules on Traffic Action Interference . . . . . . . . . . 20 7.6. Rules on Traffic Action Interference . . . . . . . . . . 21
7.6.1. Examples . . . . . . . . . . . . . . . . . . . . . . 21 7.6.1. Examples . . . . . . . . . . . . . . . . . . . . . . 21
8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks . 21 8. Dissemination of Traffic Filtering in BGP/MPLS VPN Networks . 22
8.1. Validation Procedures for BGP/MPLS VPNs . . . . . . . . . 22 8.1. Validation Procedures for BGP/MPLS VPNs . . . . . . . . . 23
8.2. Traffic Actions Rules . . . . . . . . . . . . . . . . . . 22 8.2. Traffic Actions Rules . . . . . . . . . . . . . . . . . . 23
9. Limitations of Previous Traffic Filtering Efforts . . . . . . 22 9. Limitations of Previous Traffic Filtering Efforts . . . . . . 23
9.1. Limitations in Previous DDoS Traffic Filtering Efforts . 22 9.1. Limitations in Previous DDoS Traffic Filtering Efforts . 23
9.2. Limitations in Previous BGP/MPLS Traffic Filtering . . . 23 9.2. Limitations in Previous BGP/MPLS Traffic Filtering . . . 24
10. Traffic Monitoring . . . . . . . . . . . . . . . . . . . . . 24 10. Traffic Monitoring . . . . . . . . . . . . . . . . . . . . . 24
11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
11.1. AFI/SAFI Definitions . . . . . . . . . . . . . . . . . . 24 11.1. AFI/SAFI Definitions . . . . . . . . . . . . . . . . . . 24
11.2. Flow Component Definitions . . . . . . . . . . . . . . . 24 11.2. Flow Component Definitions . . . . . . . . . . . . . . . 25
11.3. Extended Community Flow Specification Actions . . . . . 25 11.3. Extended Community Flow Specification Actions . . . . . 26
12. Security Considerations . . . . . . . . . . . . . . . . . . . 28 12. Security Considerations . . . . . . . . . . . . . . . . . . . 28
13. Original authors . . . . . . . . . . . . . . . . . . . . . . 28 13. Original authors . . . . . . . . . . . . . . . . . . . . . . 29
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 29 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 29
15. References . . . . . . . . . . . . . . . . . . . . . . . . . 29 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 29
15.1. Normative References . . . . . . . . . . . . . . . . . . 29 15.1. Normative References . . . . . . . . . . . . . . . . . . 29
15.2. Informative References . . . . . . . . . . . . . . . . . 31 15.2. Informative References . . . . . . . . . . . . . . . . . 31
Appendix A. Comparison with RFC 5575 . . . . . . . . . . . . . . 31 15.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Appendix A. Comparison with RFC 5575 . . . . . . . . . . . . . . 32
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 32
1. Introduction 1. Introduction
Modern IP routers contain both the capability to forward traffic Modern IP routers contain both the capability to forward traffic
according to IP prefixes as well as to classify, shape, rate limit, according to IP prefixes as well as to classify, shape, rate limit,
filter, or redirect packets based on administratively defined filter, or redirect packets based on administratively defined
policies. policies.
These traffic policy mechanisms allow the router to define match These traffic policy mechanisms allow the router to define match
rules that operate on multiple fields of the packet header. Actions rules that operate on multiple fields of the packet header. Actions
such as the ones described above can be associated with each rule. such as the ones described above can be associated with each rule.
The n-tuple consisting of the matching criteria defines an aggregate The n-tuple consisting of the matching criteria defines an aggregate
traffic flow specification. The matching criteria can include traffic Flow Specification. The matching criteria can include
elements such as source and destination address prefixes, IP elements such as source and destination address prefixes, IP
protocol, and transport protocol port numbers. protocol, and transport protocol port numbers.
This document defines a general procedure to encode flow This document defines a general procedure to encode flow
specification rules for aggregated traffic flows so that they can be specification rules for aggregated traffic flows so that they can be
distributed as a BGP [RFC5575] NLRI. Additionally, we define the distributed as a BGP [RFC4271] NLRI. Additionally, we define the
required mechanisms to utilize this definition to the problem of required mechanisms to utilize this definition to the problem of
immediate concern to the authors: intra- and inter-provider immediate concern to the authors: intra- and inter-provider
distribution of traffic filtering rules to filter (distributed) distribution of traffic filtering rules to filter (distributed)
denial-of-service (DoS) attacks. denial-of-service (DoS) attacks.
By expanding routing information with flow specifications, the By expanding routing information with Flow Specifications, the
routing system can take advantage of the ACL (Access Control List) or routing system can take advantage of the ACL (Access Control List) or
firewall capabilities in the router's forwarding path. Flow firewall capabilities in the router's forwarding path. Flow
specifications can be seen as more specific routing entries to a specifications can be seen as more specific routing entries to a
unicast prefix and are expected to depend upon the existing unicast unicast prefix and are expected to depend upon the existing unicast
data information. data information.
A flow specification received from an external autonomous system will A Flow Specification received from an external autonomous system will
need to be validated against unicast routing before being accepted. need to be validated against unicast routing before being accepted.
If the aggregate traffic flow defined by the unicast destination If the aggregate traffic flow defined by the unicast destination
prefix is forwarded to a given BGP peer, then the local system can prefix is forwarded to a given BGP peer, then the local system can
safely install more specific flow rules that may result in different safely install more specific flow rules that may result in different
forwarding behavior, as requested by this system. forwarding behavior, as requested by this system.
The key technology components required to address the class of The key technology components required to address the class of
problems targeted by this document are: problems targeted by this document are:
1. Efficient point-to-multipoint distribution of control plane 1. Efficient point-to-multipoint distribution of control plane
skipping to change at page 4, line 47 skipping to change at page 4, line 47
2. Inter-domain capabilities and routing policy support. 2. Inter-domain capabilities and routing policy support.
3. Tight integration with unicast routing, for verification 3. Tight integration with unicast routing, for verification
purposes. purposes.
Items 1 and 2 have already been addressed using BGP for other types Items 1 and 2 have already been addressed using BGP for other types
of control plane information. Close integration with BGP also makes of control plane information. Close integration with BGP also makes
it feasible to specify a mechanism to automatically verify flow it feasible to specify a mechanism to automatically verify flow
information against unicast routing. These factors are behind the information against unicast routing. These factors are behind the
choice of BGP as the carrier of flow specification information. choice of BGP as the carrier of Flow Specification information.
As with previous extensions to BGP, this specification makes it As with previous extensions to BGP, this specification makes it
possible to add additional information to Internet routers. These possible to add additional information to Internet routers. These
are limited in terms of the maximum number of data elements they can are limited in terms of the maximum number of data elements they can
hold as well as the number of events they are able to process in a hold as well as the number of events they are able to process in a
given unit of time. The authors believe that, as with previous given unit of time. The authors believe that, as with previous
extensions, service providers will be careful to keep information extensions, service providers will be careful to keep information
levels below the maximum capacity of their devices. levels below the maximum capacity of their devices.
In many deployments of BGP Flow Specification, the flow specification In many deployments of BGP Flow Specification, the Flow Specification
information has replace existing host length route advertisements. information has replace existing host length route advertisements.
Experience with previous BGP extensions has also shown that the Experience with previous BGP extensions has also shown that the
maximum capacity of BGP speakers has been gradually increased maximum capacity of BGP speakers has been gradually increased
according to expected loads. Taking into account Internet unicast according to expected loads. Taking into account Internet unicast
routing as well as additional applications as they gain popularity. routing as well as additional applications as they gain popularity.
From an operational perspective, the utilization of BGP as the From an operational perspective, the utilization of BGP as the
carrier for this information allows a network service provider to carrier for this information allows a network service provider to
reuse both internal route distribution infrastructure (e.g., route reuse both internal route distribution infrastructure (e.g., route
skipping to change at page 6, line 13 skipping to change at page 6, line 13
VRF - Virtual Routing and Forwarding instance. VRF - Virtual Routing and Forwarding instance.
PE - Provider Edge router PE - Provider Edge router
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 this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119] document are to be interpreted as described in [RFC2119]
3. Flow Specifications 3. Flow Specifications
A flow specification is an n-tuple consisting of several matching A Flow Specification is an n-tuple consisting of several matching
criteria that can be applied to IP traffic. A given IP packet is criteria that can be applied to IP traffic. A given IP packet is
said to match the defined flow if it matches all the specified said to match the defined flow if it matches all the specified
criteria. criteria.
A given flow may be associated with a set of attributes, depending on A given flow may be associated with a set of attributes, depending on
the particular application; such attributes may or may not include the particular application; such attributes may or may not include
reachability information (i.e., NEXT_HOP). Well-known or AS-specific reachability information (i.e., NEXT_HOP). Well-known or AS-specific
community attributes can be used to encode a set of predetermined community attributes can be used to encode a set of predetermined
actions. actions.
skipping to change at page 6, line 41 skipping to change at page 6, line 41
databases. Entries that are placed in the Loc-RIB are then databases. Entries that are placed in the Loc-RIB are then
associated with a given set of semantics, which is application associated with a given set of semantics, which is application
dependent. This is consistent with existing BGP applications. For dependent. This is consistent with existing BGP applications. For
instance, IP unicast routing (AFI=1, SAFI=1) and IP multicast instance, IP unicast routing (AFI=1, SAFI=1) and IP multicast
reverse-path information (AFI=1, SAFI=2) are handled by BGP without reverse-path information (AFI=1, SAFI=2) are handled by BGP without
any particular semantics being associated with them until installed any particular semantics being associated with them until installed
in the Loc-RIB. in the Loc-RIB.
Standard BGP policy mechanisms, such as UPDATE filtering by NLRI Standard BGP policy mechanisms, such as UPDATE filtering by NLRI
prefix as well as community matching and manipulation, MUST apply to prefix as well as community matching and manipulation, MUST apply to
the Flow specification defined NLRI-type, especially in an inter- the Flow Specification defined NLRI-type, especially in an inter-
domain environment. Network operators can also control propagation domain environment. Network operators can also control propagation
of such routing updates by enabling or disabling the exchange of a of such routing updates by enabling or disabling the exchange of a
particular (AFI, SAFI) pair on a given BGP peering session. particular (AFI, SAFI) pair on a given BGP peering session.
4. Dissemination of IPv4 FLow Specification Information 4. Dissemination of IPv4 FLow Specification Information
We define a "Flow Specification" NLRI type (Figure 1) that may We define a "Flow Specification" NLRI type (Figure 1) that may
include several components such as destination prefix, source prefix, include several components such as destination prefix, source prefix,
protocol, ports, and others (see Section 4.2 below). This NLRI is protocol, ports, and others (see Section 4.2 below). This NLRI is
treated as an opaque bit string prefix by BGP. Each bit string treated as an opaque bit string prefix by BGP. Each bit string
skipping to change at page 7, line 25 skipping to change at page 7, line 25
value. The NLRI length is expressed in octets. value. The NLRI length is expressed in octets.
+------------------------------+ +------------------------------+
| length (0xnn or 0xfn nn) | | length (0xnn or 0xfn nn) |
+------------------------------+ +------------------------------+
| NLRI value (variable) | | NLRI value (variable) |
+------------------------------+ +------------------------------+
Figure 1: Flow-spec NLRI for IPv4 Figure 1: Flow-spec NLRI for IPv4
Implementations wishing to exchange flow specification rules MUST use Implementations wishing to exchange Flow Specification rules MUST use
BGP's Capability Advertisement facility to exchange the Multiprotocol BGP's Capability Advertisement facility to exchange the Multiprotocol
Extension Capability Code (Code 1) as defined in [RFC4760]. The Extension Capability Code (Code 1) as defined in [RFC4760]. The
(AFI, SAFI) pair carried in the Multiprotocol Extension Capability (AFI, SAFI) pair carried in the Multiprotocol Extension Capability
MUST be the same as the one used to identify a particular application MUST be the same as the one used to identify a particular application
that uses this NLRI-type. that uses this NLRI-type.
4.1. Length Encoding 4.1. Length Encoding
o If the NLRI length value is smaller than 240 (0xf0 hex), the o If the NLRI length value is smaller than 240 (0xf0 hex), the
length field can be encoded as a single octet. length field can be encoded as a single octet.
skipping to change at page 7, line 47 skipping to change at page 7, line 47
o Otherwise, it is encoded as an extended-length 2-octet value in o Otherwise, it is encoded as an extended-length 2-octet value in
which the most significant nibble of the first byte is all ones. which the most significant nibble of the first byte is all ones.
In figure 1 above, values less-than 240 are encoded using two hex In figure 1 above, values less-than 240 are encoded using two hex
digits (0xnn). Values above 239 are encoded using 3 hex digits digits (0xnn). Values above 239 are encoded using 3 hex digits
(0xfnnn). The highest value that can be represented with this (0xfnnn). The highest value that can be represented with this
encoding is 4095. The value 241 is encoded as 0xf0f1. encoding is 4095. The value 241 is encoded as 0xf0f1.
4.2. NLRI Value Encoding 4.2. NLRI Value Encoding
The Flow specification NLRI-type consists of several optional The Flow Specification NLRI-type consists of several optional
subcomponents. A specific packet is considered to match the flow subcomponents. A specific packet is considered to match the flow
specification when it matches the intersection (AND) of all the specification when it matches the intersection (AND) of all the
components present in the specification. components present in the specification.
The encoding of each of the NLRI components begins with a type field The encoding of each of the NLRI components begins with a type field
(1 octet) followed by a variable length parameter. Section 4.2.1 to (1 octet) followed by a variable length parameter. Section 4.2.1 to
Section 4.2.12 define component types and parameter encodings for the Section 4.2.12 define component types and parameter encodings for the
IPv4 IP layer and transport layer headers. IPv6 NLRI component types IPv4 IP layer and transport layer headers. IPv6 NLRI component types
are described in [I-D.ietf-idr-flow-spec-v6]. are described in [I-D.ietf-idr-flow-spec-v6].
Flow specification components must follow strict type ordering by Flow Specification components must follow strict type ordering by
increasing numerical order. A given component type may or may not be increasing numerical order. A given component type may or may not be
present in the specification, but if present, it MUST precede any present in the specification, but if present, it MUST precede any
component of higher numeric type value. component of higher numeric type value.
All combinations of component types within a single NLRI are allowed, All combinations of component types within a single NLRI are allowed,
even if the combination makes no sense from a semantical perspective. even if the combination makes no sense from a semantical perspective.
If a given component type within a prefix in unknown, the prefix in If a given component type within a prefix in unknown, the prefix in
question cannot be used for traffic filtering purposes by the question cannot be used for traffic filtering purposes by the
receiver. Since a flow specification has the semantics of a logical receiver. Since a Flow Specification has the semantics of a logical
AND of all components, if a component is FALSE, by definition it AND of all components, if a component is FALSE, by definition it
cannot be applied. However, for the purposes of BGP route cannot be applied. However, for the purposes of BGP route
propagation, this prefix should still be transmitted since BGP route propagation, this prefix should still be transmitted since BGP route
distribution is independent on NLRI semantics. distribution is independent on NLRI semantics.
The <type, value> encoding is chosen in order to allow for future The <type, value> encoding is chosen in order to allow for future
extensibility. extensibility.
4.2.1. Type 1 - Destination Prefix 4.2.1. Type 1 - Destination Prefix
skipping to change at page 9, line 31 skipping to change at page 9, line 31
len - length of the value field for this operand encodes 1 (00) - len - length of the value field for this operand encodes 1 (00) -
4 (11) bytes. Type 3 flow component values are always encoded as 4 (11) bytes. Type 3 flow component values are always encoded as
single byte (len = 00). single byte (len = 00).
lt - less than comparison between data and value. lt - less than comparison between data and value.
gt - greater than comparison between data and value. gt - greater than comparison between data and value.
eq - equality between data and value. eq - equality between data and value.
The bits lt, gt, and eq can be combined to produce "less or equal", The bits lt, gt, and eq can be combined to produce common relational
"greater or equal", and inequality values. operators such as "less or equal", "greater or equal", and "not equal
to".
+----+----+----+----------------------------------+ +----+----+----+----------------------------------+
| lt | gt | eq | Resulting operation | | lt | gt | eq | Resulting operation |
+----+----+----+----------------------------------+ +----+----+----+----------------------------------+
| 0 | 0 | 0 | true (independent of the value) | | 0 | 0 | 0 | true (independent of the value) |
| 0 | 0 | 1 | == (equal) | | 0 | 0 | 1 | == (equal) |
| 0 | 1 | 0 | > (greater than) | | 0 | 1 | 0 | > (greater than) |
| 0 | 1 | 1 | >= (greater than or equal) | | 0 | 1 | 1 | >= (greater than or equal) |
| 1 | 0 | 0 | < (less than) | | 1 | 0 | 0 | < (less than) |
| 1 | 0 | 1 | <= (less than or equal) | | 1 | 0 | 1 | <= (less than or equal) |
skipping to change at page 12, line 48 skipping to change at page 12, line 48
Bit 7 - Don't fragment (DF) Bit 7 - Don't fragment (DF)
Bit 6 - Is a fragment (IsF) Bit 6 - Is a fragment (IsF)
Bit 5 - First fragment (FF) Bit 5 - First fragment (FF)
Bit 4 - Last fragment (LF) Bit 4 - Last fragment (LF)
4.3. Examples of Encodings 4.3. Examples of Encodings
An example of a flow specification encoding for: "all packets to An example of a Flow Specification encoding for: "all packets to
10.0.1/24 and TCP port 25". 10.0.1/24 and TCP port 25".
+------------------+----------+----------+ +------------------+----------+----------+
| destination | proto | port | | destination | proto | port |
+------------------+----------+----------+ +------------------+----------+----------+
| 0x01 18 0a 00 01 | 03 81 06 | 04 81 19 | | 0x01 18 0a 00 01 | 03 81 06 | 04 81 19 |
+------------------+----------+----------+ +------------------+----------+----------+
Decode for protocol: Decode for protocol:
+-------+----------+------------------------------+ +-------+----------+------------------------------+
| Value | | | | Value | | |
+-------+----------+------------------------------+ +-------+----------+------------------------------+
| 0x03 | type | | | 0x03 | type | |
| 0x81 | operator | end-of-list, value size=1, = | | 0x81 | operator | end-of-list, value size=1, = |
| 0x06 | value | | | 0x06 | value | |
+-------+----------+------------------------------+ +-------+----------+------------------------------+
An example of a flow specification encoding for: "all packets to An example of a Flow Specification encoding for: "all packets to
10.1.1/24 from 192/8 and port {range [137, 139] or 8080}". 10.1.1/24 from 192/8 and port {range [137, 139] or 8080}".
+------------------+----------+-------------------------+ +------------------+----------+-------------------------+
| destination | source | port | | destination | source | port |
+------------------+----------+-------------------------+ +------------------+----------+-------------------------+
| 0x01 18 0a 01 01 | 02 08 c0 | 04 03 89 45 8b 91 1f 90 | | 0x01 18 0a 01 01 | 02 08 c0 | 04 03 89 45 8b 91 1f 90 |
+------------------+----------+-------------------------+ +------------------+----------+-------------------------+
Decode for port: Decode for port:
skipping to change at page 14, line 12 skipping to change at page 14, line 12
mechanism to be designed for the three new applications of traffic mechanism to be designed for the three new applications of traffic
filtering (prevention of traffic-based, denial-of-service (DOS) filtering (prevention of traffic-based, denial-of-service (DOS)
attacks, traffic filtering in the context of BGP/MPLS VPN service, attacks, traffic filtering in the context of BGP/MPLS VPN service,
and centralized traffic control for SDN/NFV networks) requires and centralized traffic control for SDN/NFV networks) requires
coordination among service providers and/or coordination among the AS coordination among service providers and/or coordination among the AS
within a service provider. Section 8 has details on the limitation within a service provider. Section 8 has details on the limitation
of previous mechanisms and why BGP Flow Specification version 1 of previous mechanisms and why BGP Flow Specification version 1
provides a solution for to prevent DOS and aid BGP/MPLS VPN filtering provides a solution for to prevent DOS and aid BGP/MPLS VPN filtering
rules. rules.
This flow specification NLRI defined above to convey information This Flow Specification NLRI defined above to convey information
about traffic filtering rules for traffic that should be discarded or about traffic filtering rules for traffic that should be discarded or
handled in manner specified by a set of pre-defined actions (which handled in manner specified by a set of pre-defined actions (which
are defined in BGP Extended Communities). This mechanism is are defined in BGP Extended Communities). This mechanism is
primarily designed to allow an upstream autonomous system to perform primarily designed to allow an upstream autonomous system to perform
inbound filtering in their ingress routers of traffic that a given inbound filtering in their ingress routers of traffic that a given
downstream AS wishes to drop. downstream AS wishes to drop.
In order to achieve this goal, this draft specifies two application In order to achieve this goal, this draft specifies two application
specific NLRI identifiers that provide traffic filters, and a set of specific NLRI identifiers that provide traffic filters, and a set of
actions encoding in BGP Extended Communities. The two application actions encoding in BGP Extended Communities. The two application
specific NLRI identifiers are: specific NLRI identifiers are:
o IPv4 flow specification identifier (AFI=1, SAFI=133) along with o IPv4 Flow Specification identifier (AFI=1, SAFI=133) along with
specific semantic rules for IPv4 routes, and specific semantic rules for IPv4 routes, and
o BGP NLRI type (AFI=1, SAFI=134) value, which can be used to o BGP NLRI type (AFI=1, SAFI=134) value, which can be used to
propagate traffic filtering information in a BGP/MPLS VPN propagate traffic filtering information in a BGP/MPLS VPN
environment. environment.
Distribution of the IPv4 Flow specification is described in section Distribution of the IPv4 Flow Specification is described in section
6, and distibution of BGP/MPLS traffic flow specification is 6, and distibution of BGP/MPLS traffic Flow Specification is
described in section 8. The traffic filtering actions are described described in section 8. The traffic filtering actions are described
in section 7. in section 7.
5.1. Ordering of Traffic Filtering Rules 5.1. Ordering of Traffic Filtering Rules
With traffic filtering rules, more than one rule may match a With traffic filtering rules, more than one rule may match a
particular traffic flow. Thus, it is necessary to define the order particular traffic flow. Thus, it is necessary to define the order
at which rules get matched and applied to a particular traffic flow. at which rules get matched and applied to a particular traffic flow.
This ordering function must be such that it must not depend on the This ordering function must be such that it must not depend on the
arrival order of the flow specification's rules and must be arrival order of the Flow Specification's rules and must be
consistent in the network. consistent in the network.
The relative order of two flow specification rules is determined by The relative order of two Flow Specification rules is determined by
comparing their respective components. The algorithm starts by comparing their respective components. The algorithm starts by
comparing the left-most components of the rules. If the types comparing the left-most components of the rules. If the types
differ, the rule with lowest numeric type value has higher precedence differ, the rule with lowest numeric type value has higher precedence
(and thus will match before) than the rule that doesn't contain that (and thus will match before) than the rule that doesn't contain that
component type. If the component types are the same, then a type- component type. If the component types are the same, then a type-
specific comparison is performed. specific comparison is performed (see below) if the types are equal
the algorithm continues with the next component.
For IP prefix values (IP destination and source prefix) precedence is For IP prefix values (IP destination or source prefix): If the
given to the lowest IP value of the common prefix length; if the prefixes overlap, the one with the longer prefix-length has higher
common prefix is equal, then the most specific prefix has precedence. precedence. If they do not overlap the one with the lowest IP value
has higher precedence.
For all other component types, unless otherwise specified, the For all other component types, unless otherwise specified, the
comparison is performed by comparing the component data as a binary comparison is performed by comparing the component data as a binary
string using the memcmp() function as defined by the ISO C standard. string using the memcmp() function as defined by the ISO C standard.
For strings of different lengths, the common prefix is compared. If For strings with equal lengths the lowest string (memcmp) has higher
equal, the longest string is considered to have higher precedence precedence. For strings of different lengths, the common prefix is
than the shorter one. compared. If the common prefix is not equal the string with the
lowest prefix has higher precedence. If the common prefix is equal,
the longest string is considered to have higher precedence than the
shorter one.
Pseudocode: The code below shows a python3 implementation of the comparison
algorithm described above. The full python3 implementation including
unittests can be optained at https://github.com/stoffi92/flowspec-cmp
[1].
flow_rule_cmp (a, b) import itertools
{ import ipaddress
comp1 = next_component(a);
comp2 = next_component(b);
while (comp1 || comp2) {
// component_type returns infinity on end-of-list
if (component_type(comp1) < component_type(comp2)) {
return A_HAS_PRECEDENCE;
}
if (component_type(comp1) > component_type(comp2)) {
return B_HAS_PRECEDENCE;
}
if (component_type(comp1) == IP_DESTINATION || IP_SOURCE) { def flow_rule_cmp(a, b):
common = MIN(prefix_length(comp1), prefix_length(comp2)); for comp_a, comp_b in itertools.zip_longest(a.components,
cmp = prefix_compare(comp1, comp2, common); b.components):
// not equal, lowest value has precedence # If a component type does not exist in one rule
// equal, longest match has precedence # this rule has lower precedence
} else { if not comp_a:
common = return B_HAS_PRECEDENCE
MIN(component_length(comp1), component_length(comp2)); if not comp_b:
cmp = memcmp(data(comp1), data(comp2), common); return A_HAS_PRECEDENCE
// not equal, lowest value has precedence # higher precedence for lower component type
// equal, longest string has precedence if comp_a.component_type < comp_b.component_type:
} return A_HAS_PRECEDENCE
} if comp_a.component_type > comp_b.component_type:
return EQUAL; return B_HAS_PRECEDENCE
} # component types are equal -> type specific comparison
if comp_a.component_type in (IP_DESTINATION, IP_SOURCE):
# assuming comp_a.value, comp_b.value of type ipaddress
if comp_a.value.overlaps(comp_b.value):
# longest prefixlen has precedence
if comp_a.value.prefixlen > comp_b.value.prefixlen:
return A_HAS_PRECEDENCE
if comp_a.value.prefixlen < comp_b.value.prefixlen:
return B_HAS_PRECEDENCE
# components equal -> continue with next component
elif comp_a.value > comp_b.value:
return B_HAS_PRECEDENCE
elif comp_a.value < comp_b.value:
return A_HAS_PRECEDENCE
else:
# assuming comp_a.value, comp_b.value of type bytearray
if len(comp_a.value) == len(comp_b.value):
if comp_a.value > comp_b.value:
return B_HAS_PRECEDENCE
if comp_a.value < comp_b.value:
return A_HAS_PRECEDENCE
# components equal -> continue with next component
else:
common = min(len(comp_a.value), len(comp_b.value))
if comp_a.value[:common] > comp_b.value[:common]:
return B_HAS_PRECEDENCE
elif comp_a.value[:common] < comp_b.value[:common]:
return A_HAS_PRECEDENCE
# the first common bytes match
elif len(comp_a.value) > len(comp_b.value):
return A_HAS_PRECEDENCE
else:
return B_HAS_PRECEDENCE
return EQUAL
6. Validation Procedure 6. Validation Procedure
Flow specifications received from a BGP peer that are accepted in the Flow Specifications received from a BGP peer that are accepted in the
respective Adj-RIB-In are used as input to the route selection respective Adj-RIB-In are used as input to the route selection
process. Although the forwarding attributes of two routes for the process. Although the forwarding attributes of two routes for the
same flow specification prefix may be the same, BGP is still required same Flow Specification prefix may be the same, BGP is still required
to perform its path selection algorithm in order to select the to perform its path selection algorithm in order to select the
correct set of attributes to advertise. correct set of attributes to advertise.
The first step of the BGP Route Selection procedure (Section 9.1.2 of The first step of the BGP Route Selection procedure (Section 9.1.2 of
[RFC4271] is to exclude from the selection procedure routes that are [RFC4271] is to exclude from the selection procedure routes that are
considered non-feasible. In the context of IP routing information, considered non-feasible. In the context of IP routing information,
this step is used to validate that the NEXT_HOP attribute of a given this step is used to validate that the NEXT_HOP attribute of a given
route is resolvable. route is resolvable.
The concept can be extended, in the case of flow specification NLRI, The concept can be extended, in the case of Flow Specification NLRI,
to allow other validation procedures. to allow other validation procedures.
A flow specification NLRI must be validated such that it is A Flow Specification NLRI must be validated such that it is
considered feasible if and only if: considered feasible if and only if:
a) The originator of the flow specification matches the originator a) The originator of the Flow Specification matches the originator
of the best-match unicast route for the destination prefix of the best-match unicast route for the destination prefix
embedded in the flow specification. embedded in the Flow Specification.
b) There are no more specific unicast routes, when compared with b) There are no more specific unicast routes, when compared with
the flow destination prefix, that has been received from a the flow destination prefix, that has been received from a
different neighboring AS than the best-match unicast route, which different neighboring AS than the best-match unicast route, which
has been determined in step a). has been determined in step a).
By originator of a BGP route, we mean either the BGP originator path By originator of a BGP route, we mean either the BGP originator path
attribute, as used by route reflection, or the transport address of attribute, as used by route reflection, or the transport address of
the BGP peer, if this path attribute is not present. the BGP peer, if this path attribute is not present.
BGP implementations MUST also enforce that the AS_PATH attribute of a BGP implementations MUST also enforce that the AS_PATH attribute of a
route received via the External Border Gateway Protocol (eBGP) route received via the External Border Gateway Protocol (eBGP)
contains the neighboring AS in the left-most position of the AS_PATH contains the neighboring AS in the left-most position of the AS_PATH
attribute. While this rule is optional in the BGP specification, it attribute. While this rule is optional in the BGP specification, it
becomes necessary to enforce it for security reasons. becomes necessary to enforce it for security reasons.
The best-match unicast route may change over the time independently The best-match unicast route may change over the time independently
of the flow specification NLRI. Therefore, a revalidation of the of the Flow Specification NLRI. Therefore, a revalidation of the
flow specification NLRI MUST be performed whenever unicast routes Flow Specification NLRI MUST be performed whenever unicast routes
change. Revalidation is defined as retesting that clause a and change. Revalidation is defined as retesting that clause a and
clause b above are true. clause b above are true.
Explanation: Explanation:
The underlying concept is that the neighboring AS that advertises the The underlying concept is that the neighboring AS that advertises the
best unicast route for a destination is allowed to advertise flow- best unicast route for a destination is allowed to advertise flow-
spec information that conveys a more or equally specific destination spec information that conveys a more or equally specific destination
prefix. Thus, as long as there are no more specific unicast routes, prefix. Thus, as long as there are no more specific unicast routes,
received from a different neighboring AS, which would be affected by received from a different neighboring AS, which would be affected by
that filtering rule. that filtering rule.
The neighboring AS is the immediate destination of the traffic The neighboring AS is the immediate destination of the traffic
described by the flow specification. If it requests these flows to described by the Flow Specification. If it requests these flows to
be dropped, that request can be honored without concern that it be dropped, that request can be honored without concern that it
represents a denial of service in itself. Supposedly, the traffic is represents a denial of service in itself. Supposedly, the traffic is
being dropped by the downstream autonomous system, and there is no being dropped by the downstream autonomous system, and there is no
added value in carrying the traffic to it. added value in carrying the traffic to it.
7. Traffic Filtering Actions 7. Traffic Filtering Actions
This specification defines a minimum set of filtering actions that it This specification defines a minimum set of filtering actions that it
standardizes as BGP extended community values [RFC4360]. This is not standardizes as BGP extended community values [RFC4360]. This is not
meant to be an inclusive list of all the possible actions, but only a meant to be an inclusive list of all the possible actions, but only a
skipping to change at page 17, line 38 skipping to change at page 18, line 18
Implementations SHOULD provide mechanisms that map an arbitrary BGP Implementations SHOULD provide mechanisms that map an arbitrary BGP
community value (normal or extended) to filtering actions that community value (normal or extended) to filtering actions that
require different mappings in different systems in the network. For require different mappings in different systems in the network. For
instance, providing packets with a worse-than-best-effort, per-hop instance, providing packets with a worse-than-best-effort, per-hop
behavior is a functionality that is likely to be implemented behavior is a functionality that is likely to be implemented
differently in different systems and for which no standard behavior differently in different systems and for which no standard behavior
is currently known. Rather than attempting to define it here, this is currently known. Rather than attempting to define it here, this
can be accomplished by mapping a user-defined community value to can be accomplished by mapping a user-defined community value to
platform-/network-specific behavior via user configuration. platform-/network-specific behavior via user configuration.
The default action for a traffic filtering flow specification is to The default action for a traffic filtering Flow Specification is to
accept IP traffic that matches that particular rule. accept IP traffic that matches that particular rule.
This document defines the following extended communities values shown This document defines the following extended communities values shown
in Table 2 in the form 0x8xnn where nn indicates the sub-type. in Table 2 in the form 0x8xnn where nn indicates the sub-type.
Encodings for these extended communities are described below. Encodings for these extended communities are described below.
+-----------+----------------------+--------------------------------+ +-----------+----------------------+--------------------------------+
| community | action | encoding | | community | action | encoding |
+-----------+----------------------+--------------------------------+ +-----------+----------------------+--------------------------------+
| 0x8006 | traffic-rate-bytes | 2-byte ASN, 4-byte float | | 0x8006 | traffic-rate-bytes | 2-byte ASN, 4-byte float |
skipping to change at page 19, line 41 skipping to change at page 20, line 11
+---+---+---+---+---+---+---+---+ +---+---+---+---+---+---+---+---+
where S and T are defined as: where S and T are defined as:
o T: Terminal Action (bit 47): When this bit is set, the traffic o T: Terminal Action (bit 47): When this bit is set, the traffic
filtering engine will apply any subsequent filtering rules (as filtering engine will apply any subsequent filtering rules (as
defined by the ordering procedure). If not set, the evaluation of defined by the ordering procedure). If not set, the evaluation of
the traffic filter stops when this rule is applied. the traffic filter stops when this rule is applied.
o S: Sample (bit 46): Enables traffic sampling and logging for this o S: Sample (bit 46): Enables traffic sampling and logging for this
flow specification. Flow Specification.
o reserved: should always be set to 0 by the originator and not be o reserved: should always be set to 0 by the originator and not be
evaluated by the receiving BGP speaker. evaluated by the receiving BGP speaker.
The use of the Terminal Action (bit 47) may result in more than one The use of the Terminal Action (bit 47) may result in more than one
filter-rule matching a particular flow. All the flow actions from filter-rule matching a particular flow. All the flow actions from
these rules shall be collected and applied. If interfering actions these rules shall be collected and applied. If interfering actions
have been collected only the first occurence SHALL be applied. have been collected only the first occurence SHALL be applied.
However, if a single rule contains interfering actions this rule However, if a single rule contains interfering actions this rule
SHALL still be handled as described in Section 7.6. SHALL still be handled as described in Section 7.6.
skipping to change at page 20, line 44 skipping to change at page 21, line 13
This extended community is encoded as a sequence of 5 zero bytes This extended community is encoded as a sequence of 5 zero bytes
followed by the DSCP value encoded in the 6 least significant bits of followed by the DSCP value encoded in the 6 least significant bits of
6th byte. 6th byte.
Interferes with: No other BGP Flow Specification traffic action in Interferes with: No other BGP Flow Specification traffic action in
this document. this document.
7.6. Rules on Traffic Action Interference 7.6. Rules on Traffic Action Interference
Traffic actions may interfere with each other. If interfering Traffic actions may interfere with each other. If interfering
traffic actions are present for a single flow specification NLRI the traffic actions are present for a single Flow Specification NLRI the
entire flow specification (irrespective if there are any other non entire Flow Specification (irrespective if there are any other non
conflicting actions associated with the same flow specification) conflicting actions associated with the same Flow Specification)
SHALL be treated as BGP WITHDRAW. SHALL be treated as BGP WITHDRAW.
This document defines 7 traffic actions which are interfering in the This document defines 7 traffic actions which are interfering in the
following way: following way:
1. Redirect-action-communities (0x8008, 0x8108, 0x8208): 1. Redirect-action-communities (0x8008, 0x8108, 0x8208):
The three redirect-communities are mutually exclusive. Only a The three redirect-communities are mutually exclusive. Only a
single redirect community may be associated with a flow single redirect community may be associated with a Flow
specification otherwise they are interfering. Specification otherwise they are interfering.
2. All traffic-action communities (including redirect-actions): 2. All traffic-action communities (including redirect-actions):
Multiple occurences of the same (sub-type and type) traffic- Multiple occurences of the same (sub-type and type) traffic-
action associated with a flow specification are always action associated with a Flow Specification are always
interfering. interfering.
When a traffic action is defined in a standards document the handling When a traffic action is defined in a standards document the handling
of interaction with other/same traffic actions MUST be defined as of interaction with other/same traffic actions MUST be defined as
well. Invalid interactions between actions SHOULD NOT trigger a BGP well. Invalid interactions between actions SHOULD NOT trigger a BGP
NOTIFICATION. All error handling for error conditions based on NOTIFICATION. All error handling for error conditions based on
[RFC7606]. [RFC7606].
7.6.1. Examples 7.6.1. Examples
skipping to change at page 22, line 6 skipping to change at page 22, line 25
filtering requirements than Internet service providers. But also filtering requirements than Internet service providers. But also
Internet service providers may use those VPNs for scenarios like Internet service providers may use those VPNs for scenarios like
having the Internet routing table in a VRF, resulting in the same having the Internet routing table in a VRF, resulting in the same
traffic filtering requirements as defined for the global routing traffic filtering requirements as defined for the global routing
table environment within this document. This document proposes an table environment within this document. This document proposes an
additional BGP NLRI type (AFI=1, SAFI=134) value, which can be used additional BGP NLRI type (AFI=1, SAFI=134) value, which can be used
to propagate traffic filtering information in a BGP/MPLS VPN to propagate traffic filtering information in a BGP/MPLS VPN
environment. environment.
The NLRI format for this address family consists of a fixed-length The NLRI format for this address family consists of a fixed-length
Route Distinguisher field (8 bytes) followed by a flow specification, Route Distinguisher field (8 bytes) followed by a Flow Specification,
following the encoding defined above in Section 4.2 of this document. following the encoding defined above in Section 4.2 of this document.
The NLRI length field shall include both the 8 bytes of the Route The NLRI length field shall include both the 8 bytes of the Route
Distinguisher as well as the subsequent flow specification. Distinguisher as well as the subsequent Flow Specification.
+------------------------------+ +------------------------------+
| length (0xnn or 0xfn nn) | | length (0xnn or 0xfn nn) |
+------------------------------+ +------------------------------+
| Route Distinguisher (8 bytes)| | Route Distinguisher (8 bytes)|
+------------------------------+ +------------------------------+
| NLRI value (variable) | | NLRI value (variable) |
+------------------------------+ +------------------------------+
Flow-spec NLRI for MPLS Flow-spec NLRI for MPLS
Propagation of this NLRI is controlled by matching Route Target Propagation of this NLRI is controlled by matching Route Target
extended communities associated with the BGP path advertisement with extended communities associated with the BGP path advertisement with
the VRF import policy, using the same mechanism as described in "BGP/ the VRF import policy, using the same mechanism as described in "BGP/
MPLS IP VPNs" [RFC4364]. MPLS IP VPNs" [RFC4364].
Flow specification rules received via this NLRI apply only to traffic Flow Specification rules received via this NLRI apply only to traffic
that belongs to the VRF(s) in which it is imported. By default, that belongs to the VRF(s) in which it is imported. By default,
traffic received from a remote PE is switched via an MPLS forwarding traffic received from a remote PE is switched via an MPLS forwarding
decision and is not subject to filtering. decision and is not subject to filtering.
Contrary to the behavior specified for the non-VPN NLRI, flow rules Contrary to the behavior specified for the non-VPN NLRI, flow rules
are accepted by default, when received from remote PE routers. are accepted by default, when received from remote PE routers.
8.1. Validation Procedures for BGP/MPLS VPNs 8.1. Validation Procedures for BGP/MPLS VPNs
The validation procedures are the same as for IPv4. The validation procedures are the same as for IPv4.
skipping to change at page 23, line 28 skipping to change at page 23, line 48
and inter-AS communication channels. This can allow, for instance, a and inter-AS communication channels. This can allow, for instance, a
service provider to accept filtering requests from customers for service provider to accept filtering requests from customers for
address space they own. address space they own.
There are several drawbacks, however. An issue that is immediately There are several drawbacks, however. An issue that is immediately
apparent is the granularity of filtering control: only destination apparent is the granularity of filtering control: only destination
prefixes may be specified. Another area of concern is the fact that prefixes may be specified. Another area of concern is the fact that
filtering information is intermingled with routing information. filtering information is intermingled with routing information.
The mechanism defined in this document is designed to address these The mechanism defined in this document is designed to address these
limitations. We use the flow specification NLRI defined above to limitations. We use the Flow Specification NLRI defined above to
convey information about traffic filtering rules for traffic that is convey information about traffic filtering rules for traffic that is
subject to modified forwarding behavior (actions). The actions are subject to modified forwarding behavior (actions). The actions are
defined as extended communities and include (but are not limited to) defined as extended communities and include (but are not limited to)
rate-limiting (including discard), traffic redirection, packet rate-limiting (including discard), traffic redirection, packet
rewriting. rewriting.
9.2. Limitations in Previous BGP/MPLS Traffic Filtering 9.2. Limitations in Previous BGP/MPLS Traffic Filtering
Provider-based Layer 3 VPN networks, such as the ones using a BGP/ Provider-based Layer 3 VPN networks, such as the ones using a BGP/
MPLS IP VPN [RFC4364] control plane, may have different traffic MPLS IP VPN [RFC4364] control plane, may have different traffic
skipping to change at page 24, line 35 skipping to change at page 25, line 8
11.1. AFI/SAFI Definitions 11.1. AFI/SAFI Definitions
IANA maintains a registry entitled "SAFI Values". For the purpose of IANA maintains a registry entitled "SAFI Values". For the purpose of
this work, IANA updated the registry and allocated two additional this work, IANA updated the registry and allocated two additional
SAFIs: SAFIs:
+-------+------------------------------------------+----------------+ +-------+------------------------------------------+----------------+
| Value | Name | Reference | | Value | Name | Reference |
+-------+------------------------------------------+----------------+ +-------+------------------------------------------+----------------+
| 133 | IPv4 dissemination of flow specification | [this | | 133 | IPv4 dissemination of Flow Specification | [this |
| | rules | document] | | | rules | document] |
| 134 | VPNv4 dissemination of flow | [this | | 134 | VPNv4 dissemination of Flow | [this |
| | specification rules | document] | | | Specification rules | document] |
+-------+------------------------------------------+----------------+ +-------+------------------------------------------+----------------+
Table 3: Registry: SAFI Values Table 3: Registry: SAFI Values
11.2. Flow Component Definitions 11.2. Flow Component Definitions
A flow specification consists of a sequence of flow components, which A Flow Specification consists of a sequence of flow components, which
are identified by a an 8-bit component type. IANA has created and are identified by a an 8-bit component type. IANA has created and
maintains a registry entitled "Flow Spec Component Types". This maintains a registry entitled "Flow Spec Component Types". This
document defines the following Component Type Codes: document defines the following Component Type Codes:
+-------+--------------------+-----------------+ +-------+--------------------+-----------------+
| Value | Name | Reference | | Value | Name | Reference |
+-------+--------------------+-----------------+ +-------+--------------------+-----------------+
| 1 | Destination Prefix | [this document] | | 1 | Destination Prefix | [this document] |
| 2 | Source Prefix | [this document] | | 2 | Source Prefix | [this document] |
| 3 | IP Protocol | [this document] | | 3 | IP Protocol | [this document] |
skipping to change at page 29, line 5 skipping to change at page 29, line 32
1000. Such behavior may be confusing and these capabilities should 1000. Such behavior may be confusing and these capabilities should
be used with care whether manually configured or coordinated through be used with care whether manually configured or coordinated through
the protocol extensions described in this document. the protocol extensions described in this document.
13. Original authors 13. Original authors
Barry Greene, MuPedro Marques, Jared Mauch, Danny McPherson, and Barry Greene, MuPedro Marques, Jared Mauch, Danny McPherson, and
Nischal Sheth were authors on [RFC5575], and therefore are Nischal Sheth were authors on [RFC5575], and therefore are
contributing authors on this document. contributing authors on this document.
Note: Any original author of [RFC5575] who wants to work on this
draft can be added as a co-author.
14. Acknowledgements 14. Acknowledgements
The authors would like to thank Yakov Rekhter, Dennis Ferguson, Chris The authors would like to thank Yakov Rekhter, Dennis Ferguson, Chris
Morrow, Charlie Kaufman, and David Smith for their comments for the Morrow, Charlie Kaufman, and David Smith for their comments for the
comments on the original [RFC5575]. Chaitanya Kodeboyina helped comments on the original [RFC5575]. Chaitanya Kodeboyina helped
design the flow validation procedure; and Steven Lin and Jim Washburn design the flow validation procedure; and Steven Lin and Jim Washburn
ironed out all the details necessary to produce a working ironed out all the details necessary to produce a working
implementation in the original [RFC5575]. implementation in the original [RFC5575].
Additional acknowledgements for this document will be included here. Additional the authors would like to thank Alexander Mayrhofer,
The current authors would like to thank Alexander Mayrhofer and Nicolas Fevrier and Job Snijders for their comments and review.
Nicolas Fevrier for their comments and review.
15. References 15. References
15.1. Normative References 15.1. Normative References
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, [RFC0793] Postel, J., "Transmission Control Protocol", STD 7,
RFC 793, DOI 10.17487/RFC0793, September 1981, RFC 793, DOI 10.17487/RFC0793, September 1981,
<http://www.rfc-editor.org/info/rfc793>. <https://www.rfc-editor.org/info/rfc793>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black,
"Definition of the Differentiated Services Field (DS "Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers", RFC 2474, Field) in the IPv4 and IPv6 Headers", RFC 2474,
DOI 10.17487/RFC2474, December 1998, DOI 10.17487/RFC2474, December 1998,
<http://www.rfc-editor.org/info/rfc2474>. <https://www.rfc-editor.org/info/rfc2474>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271, Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006, DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>. <https://www.rfc-editor.org/info/rfc4271>.
[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, DOI 10.17487/RFC4360, Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
February 2006, <http://www.rfc-editor.org/info/rfc4360>. February 2006, <https://www.rfc-editor.org/info/rfc4360>.
[RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
2006, <http://www.rfc-editor.org/info/rfc4364>. 2006, <https://www.rfc-editor.org/info/rfc4364>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, [RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760, "Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007, DOI 10.17487/RFC4760, January 2007,
<http://www.rfc-editor.org/info/rfc4760>. <https://www.rfc-editor.org/info/rfc4760>.
[RFC4761] Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private [RFC4761] Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
LAN Service (VPLS) Using BGP for Auto-Discovery and LAN Service (VPLS) Using BGP for Auto-Discovery and
Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007, Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
<http://www.rfc-editor.org/info/rfc4761>. <https://www.rfc-editor.org/info/rfc4761>.
[RFC4762] Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private [RFC4762] Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
LAN Service (VPLS) Using Label Distribution Protocol (LDP) LAN Service (VPLS) Using Label Distribution Protocol (LDP)
Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007, Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
<http://www.rfc-editor.org/info/rfc4762>. <https://www.rfc-editor.org/info/rfc4762>.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an [RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", RFC 5226, IANA Considerations Section in RFCs", RFC 5226,
DOI 10.17487/RFC5226, May 2008, DOI 10.17487/RFC5226, May 2008,
<http://www.rfc-editor.org/info/rfc5226>. <https://www.rfc-editor.org/info/rfc5226>.
[RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J., [RFC5575] Marques, P., Sheth, N., Raszuk, R., Greene, B., Mauch, J.,
and D. McPherson, "Dissemination of Flow Specification and D. McPherson, "Dissemination of Flow Specification
Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009, Rules", RFC 5575, DOI 10.17487/RFC5575, August 2009,
<http://www.rfc-editor.org/info/rfc5575>. <https://www.rfc-editor.org/info/rfc5575>.
[RFC5668] Rekhter, Y., Sangli, S., and D. Tappan, "4-Octet AS [RFC5668] Rekhter, Y., Sangli, S., and D. Tappan, "4-Octet AS
Specific BGP Extended Community", RFC 5668, Specific BGP Extended Community", RFC 5668,
DOI 10.17487/RFC5668, October 2009, DOI 10.17487/RFC5668, October 2009,
<http://www.rfc-editor.org/info/rfc5668>. <https://www.rfc-editor.org/info/rfc5668>.
[RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
and A. Bierman, Ed., "Network Configuration Protocol and A. Bierman, Ed., "Network Configuration Protocol
(NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
<http://www.rfc-editor.org/info/rfc6241>. <https://www.rfc-editor.org/info/rfc6241>.
[RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route [RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
Origin Authorizations (ROAs)", RFC 6482, Origin Authorizations (ROAs)", RFC 6482,
DOI 10.17487/RFC6482, February 2012, DOI 10.17487/RFC6482, February 2012,
<http://www.rfc-editor.org/info/rfc6482>. <https://www.rfc-editor.org/info/rfc6482>.
[RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP [RFC7153] Rosen, E. and Y. Rekhter, "IANA Registries for BGP
Extended Communities", RFC 7153, DOI 10.17487/RFC7153, Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
March 2014, <http://www.rfc-editor.org/info/rfc7153>. March 2014, <https://www.rfc-editor.org/info/rfc7153>.
[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K. [RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
Patel, "Revised Error Handling for BGP UPDATE Messages", Patel, "Revised Error Handling for BGP UPDATE Messages",
RFC 7606, DOI 10.17487/RFC7606, August 2015, RFC 7606, DOI 10.17487/RFC7606, August 2015,
<http://www.rfc-editor.org/info/rfc7606>. <https://www.rfc-editor.org/info/rfc7606>.
[RFC7674] Haas, J., Ed., "Clarification of the Flowspec Redirect [RFC7674] Haas, J., Ed., "Clarification of the Flowspec Redirect
Extended Community", RFC 7674, DOI 10.17487/RFC7674, Extended Community", RFC 7674, DOI 10.17487/RFC7674,
October 2015, <http://www.rfc-editor.org/info/rfc7674>. October 2015, <https://www.rfc-editor.org/info/rfc7674>.
15.2. Informative References 15.2. Informative References
[I-D.ietf-idr-flow-spec-v6] [I-D.ietf-idr-flow-spec-v6]
McPherson, D., Raszuk, R., Pithawala, B., McPherson, D., Raszuk, R., Pithawala, B.,
akarch@cisco.com, a., and S. Hares, "Dissemination of Flow akarch@cisco.com, a., and S. Hares, "Dissemination of Flow
Specification Rules for IPv6", draft-ietf-idr-flow-spec- Specification Rules for IPv6", draft-ietf-idr-flow-spec-
v6-08 (work in progress), March 2017. v6-08 (work in progress), March 2017.
[RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)", [RFC4303] Kent, S., "IP Encapsulating Security Payload (ESP)",
RFC 4303, DOI 10.17487/RFC4303, December 2005, RFC 4303, DOI 10.17487/RFC4303, December 2005,
<http://www.rfc-editor.org/info/rfc4303>. <https://www.rfc-editor.org/info/rfc4303>.
15.3. URIs
[1] https://github.com/stoffi92/flowspec-cmp
Appendix A. Comparison with RFC 5575 Appendix A. Comparison with RFC 5575
This document includes numerous editorial changes to [RFC5575]. It This document includes numerous editorial changes to [RFC5575]. It
is recommended to read the entire document. The authors, however is recommended to read the entire document. The authors, however
want to point out the following technical changes to [RFC5575]: want to point out the following technical changes to [RFC5575]:
Section 4.2.3 defines a numeric operator and comparison bit Section 4.2.3 defines a numeric operator and comparison bit
combinations. In [RFC5575] the meaning of those bit combination combinations. In [RFC5575] the meaning of those bit combination
was not explicitly defined and left open to the reader. was not explicitly defined and left open to the reader.
skipping to change at page 31, line 48 skipping to change at page 32, line 32
transitivity of the other action communities at all. transitivity of the other action communities at all.
Section 7.2 introduces a new traffic filtering action (traffic- Section 7.2 introduces a new traffic filtering action (traffic-
rate-packets). This action did not exist in [RFC5575]. rate-packets). This action did not exist in [RFC5575].
Section 7.4 contains the same redirect actions already defined in Section 7.4 contains the same redirect actions already defined in
[RFC5575] however, these actions have been renamed to "rt- [RFC5575] however, these actions have been renamed to "rt-
redirect" to make it clearer that the redirection is based on redirect" to make it clearer that the redirection is based on
route-target. route-target.
Section 7.6 introduces rules how updates of flow specifications Section 7.6 introduces rules how updates of Flow Specifications
shall be handled in case they contain interfering actions. shall be handled in case they contain interfering actions.
Section 7.3 also cross-references this section. [RFC5575] did not Section 7.3 also cross-references this section. [RFC5575] did not
define this. define this.
Authors' Addresses Authors' Addresses
Susan Hares Susan Hares
Huawei Huawei
7453 Hickory Hill 7453 Hickory Hill
Saline, MI 48176 Saline, MI 48176
 End of changes. 84 change blocks. 
144 lines changed or deleted 179 lines changed or added

This html diff was produced by rfcdiff 1.46. The latest version is available from http://tools.ietf.org/tools/rfcdiff/