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Versions: 00 01
Opsec Working Group J. Gill
Internet-Draft Verizon Business
Intended status: Best Current D. Lewis
Practice P. Quinn
Expires: October 8, 2007 Cisco Systems Inc.
P. Schoenmaker
NTT America
April 6, 2007
Service Provider Infrastructure Security
draft-ietf-opsec-infrastructure-security-01
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Copyright Notice
Copyright (C) The IETF Trust (2007).
Abstract
This RFC describes best current practices for implementing Service
Provider network infrastructure protection for network elements.
This RFC complements and extends RFC 2267 and RFC 3704. RFC 2267
provides guidelines for filtering traffic on the ingress to service
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provider networks. RFC 3704 expands the recommendations described in
RFC 2267 to address operational filtering guidelines for single and
multi-homed environments. The focus of those RFCs is on filtering
packets on ingress to a network, regardless of destination, if those
packets have a spoofed source address, or if the source address fall
within "reserved" address space. Deployment of RFCs 2267 and 3704
has limited the effects of denial of service attacks by dropping
ingress packets with spoofed source addresses, which in turn offers
other benefits by ensuring that packets coming into a network
originate from validly allocated and consistent sources. This
document focuses solely on traffic destined to elements of the the
network infrastructure itself. This document presents techniques
that, together with network edge ingress filtering and RFC 2267 and
RFC 3704, provides a defense in depth approach for infrastructure
protection. This document does not present recommendations for
protocol validation (i.e. "sanity checking") nor does it address
guidelines for general security configuration.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Overview of Infrastructure Protection Techniques . . . . . . . 4
2.1. Edge Remarking . . . . . . . . . . . . . . . . . . . . . . 5
2.2. Device and Element Protection . . . . . . . . . . . . . . 5
2.3. Infrastructure Hiding . . . . . . . . . . . . . . . . . . 5
3. Edge Infrastructure Access Control Lists . . . . . . . . . . . 5
3.1. Constructing the Access List . . . . . . . . . . . . . . . 5
3.2. Other Traffic . . . . . . . . . . . . . . . . . . . . . . 6
3.3. Edge Infrastructure Conclusion . . . . . . . . . . . . . . 6
4. Edge Rewrite/Remarking . . . . . . . . . . . . . . . . . . . . 7
4.1. Edge Rewrite/Remarking Discussion . . . . . . . . . . . . 7
4.2. Edge Rewriting/Remarking Performance Considerations . . . 8
5. Device/Element Protection . . . . . . . . . . . . . . . . . . 8
5.1. Service Specific Access Control . . . . . . . . . . . . . 8
5.1.1. Common Services . . . . . . . . . . . . . . . . . . . 8
5.2. Aggregate Device Access Control . . . . . . . . . . . . . 9
5.2.1. IP Fragments . . . . . . . . . . . . . . . . . . . . . 9
5.2.2. Performance Considerations . . . . . . . . . . . . . . 9
5.2.3. Access Control Implementation Guide . . . . . . . . . 9
5.3. Device Access Authorization and Accounting . . . . . . . . 10
6. Infrastructure Hiding . . . . . . . . . . . . . . . . . . . . 10
6.1. Use Less IP . . . . . . . . . . . . . . . . . . . . . . . 10
6.2. MPLS Techniques . . . . . . . . . . . . . . . . . . . . . 10
6.3. IGP Configuration . . . . . . . . . . . . . . . . . . . . 11
6.4. Route Advertisement Control . . . . . . . . . . . . . . . 11
6.4.1. Route Announcement Filtering . . . . . . . . . . . . . 11
6.4.2. Address Core Out of RFC 1918 Space . . . . . . . . . . 11
6.5. Further obfuscation . . . . . . . . . . . . . . . . . . . 12
7. IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
7.1. Use IPv6 Edge Infrastructure Access Control Lists . . . . 13
7.2. IPv6 Infrastructure Hiding . . . . . . . . . . . . . . . . 13
8. IP Multicast . . . . . . . . . . . . . . . . . . . . . . . . . 13
9. Security Considerations . . . . . . . . . . . . . . . . . . . 13
10. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 14
11. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
11.1. Normative References . . . . . . . . . . . . . . . . . . . 14
11.2. Informative References . . . . . . . . . . . . . . . . . . 14
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 15
Intellectual Property and Copyright Statements . . . . . . . . . . 17
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1. Introduction
This RFC describes best current practices for implementing Service
Provider network infrastructure protection. This document both
refines and extends the filtering best practices outlined in RFC 2267
[RFC2267] and RFC 3704 [RFC3704] and focuses only on traffic destined
to the network infrastructure itself to protect the service provider
network from denial of service and other attacks. This document
presents techniques that, together with network edge ingress
filtering and RFC 2267 [RFC2267] and RFC 3704 [RFC3704], provides a
defense in depth approach for infrastructure protection.
Attacks targeting the network infrastructure can take many forms,
including bandwidth saturation to crafted packets destined to a
router. These attacks might use spoofed or non spoofed source
addresses. Regardless of the nature of the attack, the network
infrastructure must be protected from both accidental floods and
intentional attacks. Additionally, this protection will assist in
preventing the network elements from being used as reflectors in
attacks against others.
The techniques outlined in this document and described in section 2
below, describe best practices for infrastructure protection: edge
policy (filtering and precedence), per device traffic policy
enforcement for packets destined to a device and, limiting of address
and routing visibility to reduce exposure to limit core network --
that is provider (P) and provider edge (PE) infrastructure --
attacks. This document is targeted at network operators seeking to
limit their exposure to risks associated with denial of service
targeting the infrastructure. These techniques are designed to be
used in addition to specific protocol or application security
features implemented in network devices.
Infrastructure protection is a complex topic. While the best
practices outlines in this document do not provide perfect
protection, they can significantly improve the protection of the
network infrastructure.
2. Overview of Infrastructure Protection Techniques
This section provides an overview of recommended techniques that may
be used to protect network infrastructure. The areas described below
are not exhaustive; other mechanisms can be used to provide
additional protection. The techniques discussed in this document
have been widely deployed and have proven operational security
benefits in large networks.
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2.1. Edge Remarking
Edge Remarking, detailed in section 4, ensures that ingress IP
precedence or DSCP values match expected values within the context of
security. This provides another layer of defense, particularly for
traffic permitted through any of the Edge Infrastructure Access
Control Lists. This document focuses only on using Edge Remarking
best practices to enforce security policies.
2.2. Device and Element Protection
Each network infrastructure device should enforce local rules for
traffic destined to itself. These rules can take the form of filters
(permit/deny) or rate limiting rules that allow ingress traffic at
specified rates. These should complement any existing Edge
Infrastructure Access Control Lists and are described in more detail
in section 5. The deployment of these local device protection rules
complements the edge techniques by protecting the device from traffic
that: i) was permitted but violates device policy, ii) could not be
filtered at the edge, iii) entered the network on an interface that
did not have ingress filtering enabled.
2.3. Infrastructure Hiding
Hiding the infrastructure of the network provides an elegant
mechanism for protecting the network infrastructure. If the
destination of an attack is to an infrastructure address that is
unreachable, attacks become far more difficult. Infrastructure
hiding can be achieved in several ways: i) MPLS techniques ii) IGP
configuration iii) Route advertisement control. Section 6 addresses
these infrastructure hiding techniques in detail.
3. Edge Infrastructure Access Control Lists
Edge Infrastructure Access Control Lists (EIACLs) are a specific
implementation of the more general Ingress Access List. As opposed
to generic ingress filtering which denies data (sometimes referred to
as user) plane traffic, edge infrastructure access control lists do
not attempt to deny transit traffic; rather, this form of access
control limits traffic destined to infrastructure equipment while
permitting -- if needed, explicitly -- traffic through the network.
3.1. Constructing the Access List
Edge Infrastructure Access Control Lists permit only required traffic
destined to the network infrastructure, while allowing data plane
traffic to flow through unfiltered. The basic premise of EIACLs is
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that only a relatively limited subset of traffic sourced from outside
an AS should be allowed to transit towards a core router and that by
explicitly permitting only that known and understood traffic the core
devices are not subjected to unnecessary traffic that might result in
a denial of service. Since edge infrastructure access control lists
protect only the infrastructure, the development of the list differs
somewhat from "traditional" access filter lists:
1. Review addressing scheme, and identify address block(s) that
represent core devices.
2. Determine what traffic must be destined to the core devices from
outside the AS.
3. Create a filter that allows the required traffic, denies all
traffic destined to the core address block and then finally,
permits all other traffic.
4. Optionally, prior to implementing the deny action for all traffic
destined to the core address block, a log action may be used and
the results of the deny actions evaluated.
As with other ingress filtering techniques, EIACLs are applied on
ingress interfaces, as close to the edge as possible. Comprehensive
coverage (i.e. on as many interfaces as possible) yields the most
protection.
3.2. Other Traffic
In addition to the explicitly permitted traffic, EIACLs can be
combined with other common edge filters such as: 1. Source spoof
prevention (as per RFC 3704 [RFC3704]) by denying internal AS
addresses as external sources. 2. Filtering of reserved addresses
(e.g. RFC 1918 [RFC1918] addresses) since traffic should not be
sourced from reserved address. 3. Other unneeded or unnecessary
traffic. Filtering this traffic can be part of the list explicitly
or implicitly; explicit filters often provide log-able information
that can be of use during a security audit.
3.3. Edge Infrastructure Conclusion
Edge Infrastructure Access Control Lists provide a very effective
first line of defense. EIACLs are not perfect and cannot protect the
network against every attack. Furthermore, to be manageable, EIACLs
must be able to clearly and simply identify infrastructure address
space. To be effective, the EIACLs should be deployed as widely as
possible at the edge of the network on devices that support the
required filtering performance characteristics.
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The potential impact on the device's performance must be taken into
consideration when deploying EIACLs.
4. Edge Rewrite/Remarking
Typically edge packet rewrite/remarking deals primarily with traffic
passing through a device. However, IP Precedence/DSCP values are
used in prioritizing traffic sent to the devices as well. RFC 1812
[RFC1812] section 5.3 defines the use of IP Precedence in IPv4
packets for routing, management and control traffic. In addition,
the RFC [RFC1812] recommends that devices use a mechanism for
providing preferential forwarding for packets marked as routing,
management or control traffic using IP Preference bits 6 or 7 (110 or
111 in binary). RFC 2474 [RFC2474] defines DSCP and the
compatibility of IP Preference bits when using DSCP.
All packets received by customer- and peer-facing Provider Edge (PE)
router interfaces with IP Preference values of 6 or 7 or DSCP bits of
11xxxx, as specified in RFC2474 [RFC2474] Differentiated Services
Field Definition, should have the IP Preference bits rewritten.
Routing traffic received from customer- and peer-facing interfaces
can safely have the IP Preference bits rewritten because only a
limited number of protocols are transmitted beyond the first PE
router. The bits may be rewritten to any value other than IP
Preference values 6 or 7, or any DSCP value other than 11xxxx. The
new value can be based on the network operators IP Preference or DSCP
policy. If no policy exists the bits should be rewritten to 0. In
cases where control, management, and routing traffic enters the
provider network via the customer and peer facing interfaces policy
should be employed to ensure proper prioritization of critical
traffic. EIACLs may be be used facilitate the proper classification
of traffic. To offer fully transparent service, a provider may not
wish to modify the IP precedence on transit traffic through the
network. If a provider has alternate means of applying different
prioritization to router management and control traffic and transit
traffic then rewriting IP precedence bits is not required.
4.1. Edge Rewrite/Remarking Discussion
By default router vendors do not differentiate an interface on a PE
router connected to a P router from an interface connected to a CE
router. As a result any packet with the proper IP Preference or DSCP
bits set may receive the same preferential forwarding behavior as
legitimate routing, management, and control traffic. A malicious
attack may be able to take advantage of the vulnerability to increase
the effectiveness of the attack or to attack the routing, management,
and/or control traffic directly. The forwarding prioritization given
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to routing, management, and control traffic by default leaves devices
vulnerable to indirect attacks to the infrastructure. By rewriting
the IP Precedence at the PE protection is provided for both traffic
through the network along with traffic that is to the network that is
not blocked by other methods discussed in this document. This
document assumes that all customer and peer facing interfaces cannot
be trusted for inter- domain diff-serv. In cases where a trust
relationship exists for inter-domain diff-serv, diff-serv bits
1xxxxxxx do not have to be rewritten.
4.2. Edge Rewriting/Remarking Performance Considerations
The potential impact on the device's performance must be taken into
consideration when rewriting/remarking IP Precedence/DSCP bits.
Devices may require additional resources to rewrite/remark packets
compared to merely forwarding them.
5. Device/Element Protection
Even with the widest possible deployment of the techniques described
above in section 3, Infrastructure Edge Access Control, the
individual devices of the network must implement access control
mechanisms. In addition to the cases incomplete or imperfect
deployment of edge infrastructure controls, threats may come from
from trusted sources within the perimeter of the network.
5.1. Service Specific Access Control
Many vendor's implementation of service specific controls are not
made with overall system availability as a primary concern. With
this in mind, it is recommended that these controls be used in
conjunction with any aggregate mechanisms to control device access as
well as techniques like EIACLs and Core Hiding. There are many
practical examples available of vendor specific service security
mechanisms, the references section provides links to several of them.
These should guide the operator in securing the services that they
enable.
5.1.1. Common Services
While each service implemented by network equipment manufacturers
differs in its available security features there are some common
services and security features for those services that have been
widely deployed. The most important first step for the operator is
to disable any unneeded/unused services. This reduces the device's
profile. If the device is not listening to a port, it is much more
difficult to attack via that port. Second, the operator should
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utilize the services access control mechanisms to limit the access to
the devices service to only required sources. Examples of per
service security are using virtual terminal access control lists, or
SNMP Community access control lists.
5.2. Aggregate Device Access Control
Aggregating the security policy -- as opposed to defining it on a per
service basis -- allows for a simplified view of the access policies
traffic going to the device. Many vendors leverage this simplified
view to allow for the policy to be implemented in hardware,
protecting the device's control plane. A key requirement of these
mechanisms is that it must not impact transit data plane traffic.
5.2.1. IP Fragments
Traffic destined to a router is not typically fragmented. Use of
mechanisms to deny fragments to the device are recommended.
5.2.2. Performance Considerations
Care should be taken to understand a vendors implementation of
aggregate device access control and to make sure that device
operation is not impaired during DoS attacks against the device.
5.2.3. Access Control Implementation Guide
Implementing a complex set of access controls for all traffic going
to and from a router is non trivial. The following is a recommended
set of steps that has been used successfully by many carriers.
1. Develop list of required protocols.
2. Develop source address requirements: Determine destination
interface on router Does the protocol access a single interface?
Does the protocol access many interfaces? Does the protocol
access a virtual or physical interfaces?
3. Prior to implementing with a deny, it is recommended to test the
behavior with the action of "log" and observe the results
4. Deployment should be an iterative process: Start with relatively
open lists then tighten as needed
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5.3. Device Access Authorization and Accounting
Operators should use per command authorization and accounting
wherever possible. Aside from their utility in mitigating other
security threats, they provide an invaluable tool in the post event
forensics.
6. Infrastructure Hiding
Hiding the infrastructure of the network provides one layer of
protection to the devices that make up the network core. By hiding
those devices (making them unreachable) successful execution of
denial of service attacks becomes far more difficult. Before
implementing measures to make network infrastructure unreachable from
outside consider carefully that these actions can create limitations
that staff, customers, and applications may not expect and weigh
these results against the additional security afforded by a hiding
the network core. The following sections present different options
for accomplishing infrastructure hiding. The operator should
carefully consider the merits of each approach based on their
network's architecture.
6.1. Use Less IP
One way to reduce exposure of network infrastructure is to use
unnumbered links wherever possible. This is particularly useful in
the simple case of a customer with single link used as their default
path to the Internet. Not only can such a configuration reduce the
exposure of the equipment on both ends of the link to malicious
attack, the overall effort required to manage a link can be reduced
considerably with a simplified configuration and without the
additional overhead and expense of managing the IP addresses.
6.2. MPLS Techniques
While it may not be feasible to hide the entire infrastructure of
large networks, it is certainly possible to reduce exposure of
critical core infrastructure by hiding the existence and complexity
of that infrastructure using an MPLS mesh where TTL is not
decremented as packets pass through it as described in RFC 3443
[RFC3443]. In this manner the number, addresses, and even existence
of intermediary devices can be hidden from traffic as it passes
through the core. As pointed out by RFC 4381 [RFC4381], not only can
this method hide the structure, it simplifies access restrictions to
core devices. e.g. Core equipment addresses are inaccessible from
the "Public Internet" VPN. The fact that this technique is
transparent from a layer-3 viewpoint recommends it to providers of
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public services. Because basic external troubleshooting and presents
to all external views a simplified network structure with few
potential target addresses exposed it offers a better balance of
security against effort than most techniques for public networks.
6.3. IGP Configuration
Using a non-IP control plane for the core routing protocol can
substantially reduce the number of IP addresses that comprise (and
therefore, expose) the core. This simplifies the task of maintaining
edge ACLs or route announcement filters. IS-IS is an elegant and
mature protocol that some operators have found suitable for this
task.
6.4. Route Advertisement Control
6.4.1. Route Announcement Filtering
Inasmuch as it is unavoidable that some network elements must be
configured with IP addresses, it may be possible to assign these
address out of netblocks for which the routing advertisement can be
filtered out, thereby limiting possible sources of traffic to core
netblocks down to customers for whom you provide a default route, or
direct peers who would make the effort to create a static route for
your core netblock into your AS. By assigining address for network
infrastructure out of a limited number of address blocks which are
well known to internal network administrators, the operator can
greatly simplify EIACL configuration. This can also minimise the
frequency with which ACLs need to be updated based on changes in the
network. This can also have performance implications, especially for
equipment where the length of ACLs is limited. By keeping ACLs short
they may be deployable on a wider range of existing equipment.
Further, it may be possible in those situations where customer point-
to-point links must be numbered, to address such links out of another
range of addresses for which announcements could be similarly
filtered. While this has implications for a customer's ability to
remote-monitor their circuit, this can often be overcome with
application of an address from the customer's routed space to the CPE
loopback.
6.4.2. Address Core Out of RFC 1918 Space
In addition to filtering the visibility of core addresses to the
wider Internet, it may be possible to use private RFC 1918 [RFC1918]
netblocks for numbering infrastructure when IP addresses are required
(eg, loopbacks). This added level of obscurity takes prevention of
wide distribution of your infrastructure address space one step
further. Many networks filter out packets with RFC 1918 [RFC1918]
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address at ingress/ egress points as a matter of course. In this
circumstance, tools such as traceroute can work for operations and
support staff but not from outside networks. Care should be taken to
limit reverse-resolution of descriptive DNS names to queries from
internal/support groups. The fact that this technique can break
simple troubleshooting tools such as traceroute may frustrate
customers who expect to be able to perform basic troubleshooting
tasks on their own. Campus or corporate networks may find some
advantage to this configuration, on balance. Use caution when
employing this technique, particularly in public internet service
provider environments.
6.5. Further obfuscation
The strategy of changing services to run on ports different from the
default and well-known ones will not protect you from a determined
attacker. It can, however, provide some level of protection from
many attack tools, worms, auto-rooters, etc. Should they find access
to the infrastructure equipment in some way. Again, this does
nothing to restrict access, nor to make network devices more
difficult to reach. As with the other methods, a careful
consideration of how much effort and management each strategy
requires must be weighed against the protection that it provides and
the necessity of that protection in light of all measures taken to
protect a network.
7. IPv6
IPv6 Networks contain the same infrastructure security risks as IPv4.
All techniques described in this document for IPv4 should be directly
applicable to IPv6 networks. Limitations exist where devices do not
have feature parity between IPv4 and IPv6. Different techniques
maybe required where IPv4 and IPv6 networks deviate in
implementation. Multi-vendor networks can create greater
difficulties when each vendor does not have feature parity with each
other. Hardware differences in devices that support both IPv4 and
IPv6 must also be taken into consideration. Because IPv6 uses a
longer address space the scaling, and performance characteristics of
ACLs maybe lower for IPv6 vs IPv4. The fields or number of fields
that an ACL can match on may also differ. The fact that all PE
devices do not support all the recommended IPv6 security features
should not preclude the implementation of the recommendations in this
document on the devices that do support the security features. With
the number of Network Operators deploying IPv6 growing, along with
the continued availability of IPv6 Tunnel services, connecting to the
IPv6 Internet is less difficult. Dual stack IPv6 networks run on
Networks with speeds equal to IPv4. Neither the edge nor the core
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limit potential IPv6 attacks. Despite the increased deployment of
IPv6 it still does not have the same level of operational experience
as IPv4.
7.1. Use IPv6 Edge Infrastructure Access Control Lists
IPv6 Infrastructure security policy will be similar to the IPv4
policy for EIACLs, Edge remarking and Device and Element protection.
Construction of the IPv6 EIACL should use the same process as the
IPv4 EIACL. The construction of the EIACL can be made less difficult
with IPv6 because of the sparse address assignment capability given
the larger total address space. IPv6 DSCP bits should be rewritten
in the same manner that IPv4 DSCP bits. Differences between DSCP
rewriting of IPv4 and IPv6 will minimal except in cases where the
device capabilities differ between IPv4 and IPv6. Device and Element
protection should be created using the same methods described in this
document for IPv4. The policy may differ for IPv6 from IPv4 in cases
where services are exclusively IPv4 or exclusively IPv6. Services
not used with IPv6 should be disabled.
7.2. IPv6 Infrastructure Hiding
Network operators may deploy IPv4 differently from IPv6 in their
network. Providers may use native forwarding for IPv6 while using
MPLS for IPv4, other combinations. IPv6 infrastructure hiding should
have parity with IPv4 infrastructure hiding even if the technique
used is different. Implementation of IPv6 route advertisement
control for infrastructure hiding is difficult when using global
address space. Registeries assign fewer large blocks of IPv6 space
compared to IPv4. Providers cannot control the announcement of
infrastructure global IPv6 blocks for infrastructure hiding without
deaggregating their IPv6 announcements.
8. IP Multicast
IP Multicast behaves differently from IP unicast therefore must be
secured in a different manner. Some of the protocols used with
multicast rely on IP unicast to transport the routing, and control
information. Unicast based protocols should be secured using the
technique described in much of this document. Multicast security is
better addressed in a multicast specific security document.
9. Security Considerations
This entire document is concerned with security.
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10. Acknowledgements
Don Smith provided invaluable comments and suggestions. Pat Cain,
Ross Callon, Vince Fuller, Barry Greene, George Jones, David Meyer,
Peka Savola reviewed this document and provided feedback.
11. References
11.1. Normative References
[RFC1812] Baker, F., Ed., "Requirements for IP Version 4 Routers",
June 1995.
[RFC1918] Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.
J., Lear, E., "Address Allocation for Private Internets",
February 1996.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2474] Nichols, K., Blake, S., Baker, F., Black, D., "Definition
of the Differentiated Services Field (DS Field) in the
IPv4 and IPv6 Headers", December 1998.
[RFC3443] Agarwal, P., Akyol, B., "Time To Live (TTL) Processing in
Multi-Protocol Label Switching (MPLS) Networks",
January 2003.
[RFC3704] Baker, F., Savola, P., "Ingress Filtering for Multihomed
Networks", March 2004.
[RFC4381] Behringer, M., "Analysis of the Security of BGP/MPLS IP
Virtual Private Networks (VPNs)", February 2006.
11.2. Informative References
[AKIN] "Hardening Cisco Routers", T. Akin, O'Reilly Media,
2002, ISBN 0596001665.
[CYMRU-J] "JUNOS Secure Template", S. Gill, Team Cymru, March 2005,
http://www.cymru.com/gillsr/documents/junos-template.pdf
[CYMRU-C] "Secure IOS Template", R. Thomas, Team Cymru, March 2007,
http://www.cymru.com/Documents/secure-ios-template.html
[GREENE] "Cisco ISP Essentials", B. Greene and P. Smith,
Cisco Press, 2002, ISBN 1587050412.
[NANOG-M] "Implications of Securing Backbone Router
Infrastructure", R. McDowell, NANOG 31, May 2004.
http://www.nanog.org/mtg-0405/mcdowell.html
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[RFC2334] Narten, T., and H. Alverstand, "Guidelines for Writing an
IANA Considerations Section in RFCs", October 1998.
[RFC2827] Ferguson, P., Senie, D., "Network Ingress Filtering:
Defeating Denial of Service Attacks which employ IP Source
Address Spoofing", May 2000.
[RFC3669] Bradner, S., "Intellectual Property Rights in IETF
Technology", February 2004.
[RFC3871] Jones, G., Ed., "Operational Security Requirements for
Large Internet Service Provider (ISP) IP Network
Infrastructure", September 2004.
[RFC3978] Bradner, S., Ed., "IETF Rights in Contributions",
February 2004.
[RFC4778] Kaeo, M., "Current Operational Security Practices in
Internet Service Provider Environments", January 2007.
Authors' Addresses
James Gill
Verizon Business
22001 Louden County Parkway
Ashburn, VA 20147
US
Phone: +1-703-886-3834
Email: james.gill@verizonbusiness.com
URI: www.verizonbusiness.com
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Darrel Lewis
Cisco Systems Inc.
170 West Tasman Dr.
San Jose, CA 95134
US
Phone: +1-408-853-3653
Email: darlewis@cisco.com
URI: www.cisco.com
Paul Quinn
Cisco Systems Inc.
170 West Tasman Drive
San Jose, CA 95134
US
Phone: +1-408-527-3560
Email: paulq@cisco.com
URI: www.cisco.com
Peter Schoenmaker
NTT America
101 Park Ave., FL 41
New York, NY 10178
US
Phone: +1-202-808-2298
Fax:
Email: pds@ntt.net
URI:
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Full Copyright Statement
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