draft-ietf-intarea-router-alert-considerations-03.txt   draft-ietf-intarea-router-alert-considerations-04.txt 
Network Working Group F. Le Faucheur, Ed. Network Working Group F. Le Faucheur, Ed.
Internet-Draft Cisco Internet-Draft Cisco
Intended status: BCP March 10, 2011 Intended status: BCP June 7, 2011
Expires: September 11, 2011 Expires: December 9, 2011
IP Router Alert Considerations and Usage IP Router Alert Considerations and Usage
draft-ietf-intarea-router-alert-considerations-03 draft-ietf-intarea-router-alert-considerations-04
Abstract Abstract
The IP Router Alert Option is an IP option that alerts transit The IP Router Alert Option is an IP option that alerts transit
routers to more closely examine the contents of an IP packet. RSVP, routers to more closely examine the contents of an IP packet. RSVP,
PGM, IGMP/MLD, MRD and GIST are some of the protocols that make use PGM, IGMP/MLD, MRD and GIST are some of the protocols that make use
of the IP Router Alert option. This document discusses security of the IP Router Alert option. This document discusses security
aspects and usage guidelines around the use of the current IP Router aspects and usage guidelines around the use of the current IP Router
Alert option. Specifically, it provides recommendation against using Alert option. Specifically, it provides recommendation against using
the Router Alert in the end-to-end open Internet as well as identify the Router Alert in the end-to-end open Internet as well as identify
skipping to change at page 1, line 40 skipping to change at page 1, line 40
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This Internet-Draft will expire on September 11, 2011. This Internet-Draft will expire on December 9, 2011.
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Table of Contents Table of Contents
1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Conventions Used in This Document . . . . . . . . . . . . 4 1.1. Conventions Used in This Document . . . . . . . . . . . . 3
2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 2. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Security Concerns of Router Alert . . . . . . . . . . . . . . 7 3. Security Concerns of Router Alert . . . . . . . . . . . . . . 6
4. Guidelines for use of Router Alert . . . . . . . . . . . . . . 10 4. Guidelines for use of Router Alert . . . . . . . . . . . . . . 9
4.1. Use of Router Alert End-to-End In the Internet (Router 4.1. Use of Router Alert End-to-End In the Internet (Router
Alert in Peer Model) . . . . . . . . . . . . . . . . . . . 10 Alert in Peer Model) . . . . . . . . . . . . . . . . . . . 9
4.2. Use of Router Alert In Controlled Environments . . . . . . 11 4.2. Use of Router Alert In Controlled Environments . . . . . . 10
4.2.1. Use of Router Alert Within an Administrative Domain . 11 4.2.1. Use of Router Alert Within an Administrative Domain . 10
4.2.2. Use of Router Alert In Overlay Model . . . . . . . . . 13 4.2.2. Use of Router Alert In Overlay Model . . . . . . . . . 12
4.3. Router Alert Protection Approaches for Service 4.3. Router Alert Protection Approaches for Service
Providers . . . . . . . . . . . . . . . . . . . . . . . . 16 Providers . . . . . . . . . . . . . . . . . . . . . . . . 15
5. Guidelines for Router Alert Implementation . . . . . . . . . . 18 5. Guidelines for Router Alert Implementation . . . . . . . . . . 17
6. Security Considerations . . . . . . . . . . . . . . . . . . . 19 6. Security Considerations . . . . . . . . . . . . . . . . . . . 18
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19
8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 21 8. Contributors . . . . . . . . . . . . . . . . . . . . . . . . . 20
9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 22 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 21
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 23 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 22
10.1. Normative References . . . . . . . . . . . . . . . . . . . 23 10.1. Normative References . . . . . . . . . . . . . . . . . . . 22
10.2. Informative References . . . . . . . . . . . . . . . . . . 23 10.2. Informative References . . . . . . . . . . . . . . . . . . 22
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 25 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 24
1. Terminology 1. Terminology
For readability, this document uses the following loosely defined For readability, this document uses the following loosely defined
terms: terms:
o Slow path : Software processing path for packets o Slow path : Software processing path for packets
o Fast path : ASIC/Hardware processing path for packets o Fast path : ASIC/Hardware processing path for packets
o Next level protocol: the protocol transported in the IP datagram. o Next level protocol: the protocol transported in the IP datagram.
In IPv4 [RFC0791], the next level protocol is identified by the In IPv4 [RFC0791], the next level protocol is identified by the
IANA protocol number conveyed in the 8-bit "Protocol" field in the IANA protocol number conveyed in the 8-bit "Protocol" field in the
IPv4 header. In IPv6 [RFC1883], the next level protocol is IPv4 header. In IPv6 [RFC2460], the next level protocol is
identified by the IANA protocol number conveyed in the 8-bit "Next identified by the IANA protocol number conveyed in the 8-bit "Next
Header" field in the IPv6 header. Header" field in the IPv6 header.
1.1. Conventions Used in This Document 1.1. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in 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].
2. Introduction 2. Introduction
[RFC2113] and [RFC2711] respectively define the IPv4 and IPv6 Router [RFC2113] and [RFC2711] respectively define the IPv4 and IPv6 Router
Alert Option (RAO). In this document, we collectively refer to those Alert Option (RAO). In this document, we collectively refer to those
as the IP Router Alert. The IP Router Alert Option is an IP option as the IP Router Alert. The IP Router Alert Option is an IP option
that alerts transit routers to more closely examine the contents of that alerts transit routers to more closely examine the contents of
an IP packet. an IP packet.
RSVP ([RFC2205], [RFC3175], [RFC3209]), PGM ([RFC3208]), IGMP RSVP ([RFC2205], [RFC3175], [RFC3209]), PGM ([RFC3208]), IGMP
([RFC3376]), MLD ([RFC2710], [RFC3810]), MRD ([RFC4286]) and NSIS ([RFC3376]), MLD ([RFC2710], [RFC3810]), MRD ([RFC4286]) and NSIS
General Internet Signalling Transport (GIST) ([I-D.ietf-nsis-ntlp]) General Internet Signalling Transport (GIST) ([RFC5971]) are some of
are some of the protocols that make use of the IP Router Alert. the protocols that make use of the IP Router Alert.
Section 3 describes the security concerns associated with the use of Section 3 describes the security concerns associated with the use of
the Router Alert option. the Router Alert option.
Section 4 provides guidelines for the use of Router Alert. More Section 4 provides guidelines for the use of Router Alert. More
specifically, Section 4.1 recommends that Router Alert not be used specifically, Section 4.1 recommends that Router Alert not be used
for end to end applications over the Internet, while Section 4.2 for end to end applications over the Internet, while Section 4.2
presents controlled environments where applications/protocols relying presents controlled environments where applications/protocols relying
on IP Router Alert can be deployed effectively and safely. on IP Router Alert can be deployed effectively and safely.
Section 4.3 provides recommendations on protection approaches to be Section 4.3 provides recommendations on protection approaches to be
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4.1. Use of Router Alert End-to-End In the Internet (Router Alert in 4.1. Use of Router Alert End-to-End In the Internet (Router Alert in
Peer Model) Peer Model)
Because of the security concerns associated with Router Alert Because of the security concerns associated with Router Alert
discussed in Section 3, network operators need to actively protect discussed in Section 3, network operators need to actively protect
themselves against externally generated IP Router Alert packets. themselves against externally generated IP Router Alert packets.
Because there is no convenient universal mechanisms to triage between Because there is no convenient universal mechanisms to triage between
desired and undesired router alert packets, network operators desired and undesired router alert packets, network operators
currently often protect themselves in ways that isolate them from currently often protect themselves in ways that isolate them from
externally generated IP Router Alert packets. This may (ideally) be externally generated IP Router Alert packets. This may (ideally) be
achieved by tunneling IP Router Alert packets achieved by tunneling IP Router Alert packets [RFC6178] so that the
[I-D.ietf-mpls-ip-options] so that the IP Router Alert option is IP Router Alert option is hidden through that network, or it may be
hidden through that network, or it may be achieved via mechanisms achieved via mechanisms resulting in occasional (e.g., rate limiting)
resulting in occasional (e.g., rate limiting) or systematic drop of or systematic drop of IP Router Alert packets.
IP Router Alert packets.
Thus, it is RECOMMENDED that applications and protocols not be Thus, it is RECOMMENDED that applications and protocols not be
deployed with a dependency on processing of the Router Alert option deployed with a dependency on processing of the Router Alert option
(as currently specified) across independent administrative domains in (as currently specified) across independent administrative domains in
the Internet. Figure 1 illustrates such a hypothetical use of Router the Internet. Figure 1 illustrates such a hypothetical use of Router
Alert end-to-end in the Internet. We refer to such a model of Router Alert end-to-end in the Internet. We refer to such a model of Router
Alert option use as a "Peer Model" Router Alert option use, since Alert option use as a "Peer Model" Router Alert option use, since
core routers in different administrative domains would partake in core routers in different administrative domains would partake in
processing of Router Alert option datagrams associated with the same processing of Router Alert option datagrams associated with the same
signalling flow. signalling flow.
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RSVP reservations can be used for video flows from endpoints to RSVP reservations can be used for video flows from endpoints to
endpoints through the network. endpoints through the network.
In some environments, the network administrator can reliably ensure In some environments, the network administrator can reliably ensure
that router alert packets from any untrusted device (e.g., from that router alert packets from any untrusted device (e.g., from
external routers) are prevented from entering a trusted area (e.g., external routers) are prevented from entering a trusted area (e.g.,
the internal routers). For example, this may be achieved by ensuring the internal routers). For example, this may be achieved by ensuring
that routers straddling the trust boundary (e.g., edge routers) that routers straddling the trust boundary (e.g., edge routers)
always encapsulate those packets (without setting IP Router Alert -or always encapsulate those packets (without setting IP Router Alert -or
equivalent- in the encapsulating header) through the trusted area (as equivalent- in the encapsulating header) through the trusted area (as
discussed in [I-D.ietf-mpls-ip-options]). In such environments, the discussed in [RFC6178]). In such environments, the risks of DOS
risks of DOS attacks through the IP Router Alert vector is removed in attacks through the IP Router Alert vector is removed in the trusted
the trusted area (or greatly reduced) even if IP Router Alert is used area (or greatly reduced) even if IP Router Alert is used inside the
inside the trusted area (say for RSVP-TE). Thus an application trusted area (say for RSVP-TE). Thus an application relying on IP
relying on IP Router Alert MAY be safely deployed within the trusted Router Alert MAY be safely deployed within the trusted area. A
area. A Service Provider running RSVP-TE within his network may be Service Provider running RSVP-TE within his network may be an example
an example of such protected environment. Such an environment is of such protected environment. Such an environment is illustrated in
illustrated in Figure 3. Figure 3.
-------- -------------------------- -------- -------- -------------------------- --------
/ A \ / B \ / C \ / A \ / B \ / C \
| | | (*) (*) | | | | | | (*) (*) | | |
| |-------TT | |<=============>| | TT------- | | | |-------TT | |<=============>| | TT------- | |
| | | - - | | | | | | - - | | |
\ / \ / \ / \ / \ / \ /
-------- -------------------------- -------- -------- -------------------------- --------
(*) closer examination of Router Alert option datagrams (*) closer examination of Router Alert option datagrams
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4.2.2. Use of Router Alert In Overlay Model 4.2.2. Use of Router Alert In Overlay Model
In some controlled environment: In some controlled environment:
o the sites of a network A are interconnected through a service o the sites of a network A are interconnected through a service
provider network B provider network B
o the service provider network B protects itself from IP Router o the service provider network B protects itself from IP Router
Alert messages without dropping those when they transit over the Alert messages without dropping those when they transit over the
transit network (for example using mechanisms discussed in transit network (for example using mechanisms discussed in
[I-D.ietf-mpls-ip-options]) [RFC6178])
In such controlled environment, an application relying on exchange In such controlled environment, an application relying on exchange
and handling of RAO packets (e.g., RSVP) in the network A sites (but and handling of RAO packets (e.g., RSVP) in the network A sites (but
not inside network B) MAY be safely deployed. We refer to such a not inside network B) MAY be safely deployed. We refer to such a
deployment as a use of Router Alert in a Water-Tight Overlay. deployment as a use of Router Alert in a Water-Tight Overlay.
"Overlay" because Router Alert option datagrams are used in network A "Overlay" because Router Alert option datagrams are used in network A
on top of, and completely transparently to, network B. "Water-Tight" on top of, and completely transparently to, network B. "Water-Tight"
because router alert option datagrams from A cannot leak inside because router alert option datagrams from A cannot leak inside
network B. A private enterprise intranet, whose sites are network B. A private enterprise intranet, whose sites are
interconnected through a Service Prover network, and using RSVP to interconnected through a Service Prover network, and using RSVP to
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provider network B provider network B
o the service provider B processes router alert packets on the edge o the service provider B processes router alert packets on the edge
routers and protect these edge routers against RAO based attacks routers and protect these edge routers against RAO based attacks
using mechanisms such as (possibly per port) RAO rate limiting and using mechanisms such as (possibly per port) RAO rate limiting and
filtering filtering
o the service provider network B protects its core routers from o the service provider network B protects its core routers from
Router Alert messages without dropping those when they transit Router Alert messages without dropping those when they transit
over the transit network (for example using mechanisms discussed over the transit network (for example using mechanisms discussed
in [I-D.ietf-mpls-ip-options]) in [RFC6178])
In such controlled environment, an application relying on exchange In such controlled environment, an application relying on exchange
and handling of RAO packets (e.g., RSVP) in the network A sites and and handling of RAO packets (e.g., RSVP) in the network A sites and
in network B Edges (but not in the core of network B) MAY be safely in network B Edges (but not in the core of network B) MAY be safely
deployed. We refer to such a deployment as a use of Router Alert in deployed. We refer to such a deployment as a use of Router Alert in
a Leak-Controlled Overlay. "Overlay" because Router Alert option a Leak-Controlled Overlay. "Overlay" because Router Alert option
datagrams are used in network A on top of, and completely datagrams are used in network A on top of, and completely
transparently to, network B core. "Leak-Controlled" because router transparently to, network B core. "Leak-Controlled" because router
alert option datagrams from A leak inside network B's B edges but not alert option datagrams from A leak inside network B's B edges but not
inside network B's core. A private enterprise intranet, whose sites inside network B's core. A private enterprise intranet, whose sites
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Note that the Service Provider might additionally use protocol Note that the Service Provider might additionally use protocol
specific mechanisms that reduce the dependency on Router Alert for specific mechanisms that reduce the dependency on Router Alert for
operation of this protocol inside the Service Provider environment; operation of this protocol inside the Service Provider environment;
use of RSVP refresh reduction mechanisms ([RFC2961]) would be an use of RSVP refresh reduction mechanisms ([RFC2961]) would be an
example of such mechanisms in the case where the Service Provider is example of such mechanisms in the case where the Service Provider is
running RSVP-TE within his network since this allows refresh of running RSVP-TE within his network since this allows refresh of
existing Path and Resv states without use of the IP Router Alert existing Path and Resv states without use of the IP Router Alert
option. option.
As yet another example, using mechanisms such as those discussed in As yet another example, using mechanisms such as those discussed in
[I-D.ietf-mpls-ip-options] a Service Provider can safely protect the [RFC6178] a Service Provider can safely protect the operation of a
operation of a protocol depending on IP Router Alert within his protocol depending on IP Router Alert within his network (e.g.,
network (e.g., RSVP-TE) while at the same time safely transporting IP RSVP-TE) while at the same time safely transporting IP Router Alert
Router Alert packets carrying another protocol that may be used end packets carrying another protocol that may be used end to end (e.g.,
to end (e.g., IPv4/IPv6 RSVP). We observe that while tunneling of IPv4/IPv6 RSVP). We observe that while tunneling of Router Alert
Router Alert option datagrams over an MPLS backbone as discussed in option datagrams over an MPLS backbone as discussed in [RFC6178] is
[I-D.ietf-mpls-ip-options] is well understood, tunnelling Router well understood, tunnelling Router Alert option datagrams over an
Alert option datagrams over an non-MPLS IP backbone presents a number non-MPLS IP backbone presents a number of issues (and in particular
of issues (and in particular for determining where to forward the for determining where to forward the encapsulated datagram) and is
encapsulated datagram) and is not common practise at the time of not common practise at the time of writing this document.
writing this document.
As a last resort, if the SP does not have any means to safely As a last resort, if the SP does not have any means to safely
transport end to end IP Router Alert option packets over his network, transport end to end IP Router Alert option packets over his network,
the SP MAY drop those packets. It must be noted that this has the the SP MAY drop those packets. It must be noted that this has the
undesirable consequence of preventing the use of the Router Alert undesirable consequence of preventing the use of the Router Alert
option in the Overlay Model on top of this network, and therefore option in the Overlay Model on top of this network, and therefore
prevents users of that network from deploying a number of valid prevents users of that network from deploying a number of valid
applications/protocols in their environment. applications/protocols in their environment.
5. Guidelines for Router Alert Implementation 5. Guidelines for Router Alert Implementation
It is RECOMMENDED that router implementations of IP Router Alert It is RECOMMENDED that router implementations of IP Router Alert
option include protection mechanisms against Router Alert based DOS option include protection mechanisms against Router Alert based DOS
attacks appropriate for their targeted deployment environments. For attacks appropriate for their targeted deployment environments. For
example, this can include ability on an edge router to "tunnel" IP example, this can include ability on an edge router to "tunnel" IP
Router Alert option of received packets when forwarding those over Router Alert option of received packets when forwarding those over
the core as discussed in [I-D.ietf-mpls-ip-options]. As another the core as discussed in [RFC6178]. As another example, although not
example, although not always available from current implementations, always available from current implementations, new implementations
new implementations MAY include protection mechanisms such as MAY include protection mechanisms such as selective (possibly
selective (possibly dynamic) filtering and rate-limiting of IP Router dynamic) filtering and rate-limiting of IP Router Alert option
Alert option packets. packets.
If an IP packet contains the IP Router Alert option, but the next If an IP packet contains the IP Router Alert option, but the next
level protocol is not explicitly identified as a protocol of interest level protocol is not explicitly identified as a protocol of interest
by the router examining the packet, the behavior is not explicitly by the router examining the packet, the behavior is not explicitly
defined by [RFC2113]. However, the behavior is implied and, for defined by [RFC2113]. However, the behavior is implied and, for
example, the definition of RSVP in [RFC2205] assumes that the packet example, the definition of RSVP in [RFC2205] assumes that the packet
will be forwarded using normal forwarding based on the destination IP will be forwarded using normal forwarding based on the destination IP
address. Thus, a router implementation SHOULD forward within the address. Thus, a router implementation SHOULD forward within the
"fast path" (subject to all normal policies and forwarding rules) a "fast path" (subject to all normal policies and forwarding rules) a
packet carrying the IP Router Alert option containing a next level packet carrying the IP Router Alert option containing a next level
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* tony.li@tony.li * tony.li@tony.li
9. Acknowledgments 9. Acknowledgments
We would like to thank Dave Oran, Magnus Westerlund, John Scudder, We would like to thank Dave Oran, Magnus Westerlund, John Scudder,
Ron Bonica, Ross Callon, Alfred Hines, Carlos Pignataro and Roland Ron Bonica, Ross Callon, Alfred Hines, Carlos Pignataro and Roland
Bless for their comments. This document also benefited from Bless for their comments. This document also benefited from
discussions with Jukka Manner and Suresh Krishnan. The discussion discussions with Jukka Manner and Suresh Krishnan. The discussion
about use of the value field in the IPv4 Router Alert borrowed from a about use of the value field in the IPv4 Router Alert borrowed from a
similar discussion in [I-D.ietf-nsis-ntlp]. similar discussion in [RFC5971].
10. References 10. References
10.1. Normative References 10.1. Normative References
[RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791,
September 1981. September 1981.
[RFC1883] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 1883, December 1995.
[RFC2113] Katz, D., "IP Router Alert Option", RFC 2113, [RFC2113] Katz, D., "IP Router Alert Option", RFC 2113,
February 1997. February 1997.
[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", RFC 2460, December 1998. (IPv6) Specification", RFC 2460, December 1998.
[RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option", [RFC2711] Partridge, C. and A. Jackson, "IPv6 Router Alert Option",
RFC 2711, October 1999. RFC 2711, October 1999.
[RFC5350] Manner, J. and A. McDonald, "IANA Considerations for the [RFC5350] Manner, J. and A. McDonald, "IANA Considerations for the
IPv4 and IPv6 Router Alert Options", RFC 5350, IPv4 and IPv6 Router Alert Options", RFC 5350,
September 2008. September 2008.
10.2. Informative References 10.2. Informative References
[I-D.ietf-mpls-ip-options]
Jaeger, W., Mullooly, J., Scholl, T., and D. Smith, "Label
Edge Router Forwarding of IPv4 Option Packets",
draft-ietf-mpls-ip-options-07 (work in progress),
December 2010.
[I-D.ietf-nsis-ntlp]
Schulzrinne, H. and M. Stiemerling, "GIST: General
Internet Signalling Transport", draft-ietf-nsis-ntlp-20
(work in progress), June 2009.
[I-D.krishnan-ipv6-hopbyhop] [I-D.krishnan-ipv6-hopbyhop]
Krishnan, S., "The case against Hop-by-Hop options", Krishnan, S., "The case against Hop-by-Hop options",
draft-krishnan-ipv6-hopbyhop-05 (work in progress), draft-krishnan-ipv6-hopbyhop-05 (work in progress),
October 2010. October 2010.
[I-D.narayanan-rtg-router-alert-extension] [I-D.narayanan-rtg-router-alert-extension]
Narayanan, A., Faucheur, F., Ward, D., and R. Rahman, "IP Narayanan, A., Faucheur, F., Ward, D., and R. Rahman, "IP
Router Alert Option Extension", Router Alert Option Extension",
draft-narayanan-rtg-router-alert-extension-00 (work in draft-narayanan-rtg-router-alert-extension-00 (work in
progress), March 2009. progress), March 2009.
skipping to change at page 24, line 45 skipping to change at page 23, line 32
[RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery [RFC3810] Vida, R. and L. Costa, "Multicast Listener Discovery
Version 2 (MLDv2) for IPv6", RFC 3810, June 2004. Version 2 (MLDv2) for IPv6", RFC 3810, June 2004.
[RFC4081] Tschofenig, H. and D. Kroeselberg, "Security Threats for [RFC4081] Tschofenig, H. and D. Kroeselberg, "Security Threats for
Next Steps in Signaling (NSIS)", RFC 4081, June 2005. Next Steps in Signaling (NSIS)", RFC 4081, June 2005.
[RFC4286] Haberman, B. and J. Martin, "Multicast Router Discovery", [RFC4286] Haberman, B. and J. Martin, "Multicast Router Discovery",
RFC 4286, December 2005. RFC 4286, December 2005.
[RFC5971] Schulzrinne, H. and R. Hancock, "GIST: General Internet
Signalling Transport", RFC 5971, October 2010.
[RFC6016] Davie, B., Le Faucheur, F., and A. Narayanan, "Support for [RFC6016] Davie, B., Le Faucheur, F., and A. Narayanan, "Support for
the Resource Reservation Protocol (RSVP) in Layer 3 VPNs", the Resource Reservation Protocol (RSVP) in Layer 3 VPNs",
RFC 6016, October 2010. RFC 6016, October 2010.
[RFC6178] Smith, D., Mullooly, J., Jaeger, W., and T. Scholl, "Label
Edge Router Forwarding of IPv4 Option Packets", RFC 6178,
March 2011.
Author's Address Author's Address
Francois Le Faucheur (editor) Francois Le Faucheur (editor)
Cisco Systems Cisco Systems
Greenside, 400 Avenue de Roumanille Greenside, 400 Avenue de Roumanille
Sophia Antipolis 06410 Sophia Antipolis 06410
France France
Phone: +33 4 97 23 26 19 Phone: +33 4 97 23 26 19
Email: flefauch@cisco.com Email: flefauch@cisco.com
 End of changes. 20 change blocks. 
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