draft-ietf-v6ops-6to4-to-historic-04.txt   draft-ietf-v6ops-6to4-to-historic-05.txt 
v6ops WG O. Troan v6ops WG O. Troan
Internet-Draft Cisco Internet-Draft Cisco
Obsoletes: 3056, 3068 June 6, 2011 Obsoletes: 3056, 3068 June 24, 2011
(if approved) (if approved)
Intended status: Informational Intended status: Informational
Expires: December 8, 2011 Expires: December 26, 2011
Request to move Connection of IPv6 Domains via IPv4 Clouds (6to4) to Request to move Connection of IPv6 Domains via IPv4 Clouds (6to4) to
Historic status Historic status
draft-ietf-v6ops-6to4-to-historic-04.txt draft-ietf-v6ops-6to4-to-historic-05.txt
Abstract Abstract
Experience with the "Connection of IPv6 Domains via IPv4 Clouds Experience with the "Connection of IPv6 Domains via IPv4 Clouds
(6to4)" IPv6 transitioning mechanism has shown that the mechanism is (6to4)" IPv6 transitioning mechanism has shown that the mechanism is
unsuitable for widespread deployment and use in the Internet. This unsuitable for widespread deployment and use in the Internet. This
document requests that RFC3056 and the companion document "An Anycast document requests that RFC3056 and the companion document "An Anycast
Prefix for 6to4 Relay Routers" RFC3068 are moved to historic status. Prefix for 6to4 Relay Routers" RFC3068 are made obsolete and moved to
historic status.
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 http://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 December 8, 2011. This Internet-Draft will expire on December 26, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2011 IETF Trust and the persons identified as the Copyright (c) 2011 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 (http://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
skipping to change at page 2, line 17 skipping to change at page 2, line 18
1. Introduction 1. Introduction
There would appear to be no evidence of any substantial deployment of There would appear to be no evidence of any substantial deployment of
the variant of 6to4 described in [RFC3056]. Its extension specified the variant of 6to4 described in [RFC3056]. Its extension specified
in "An Anycast Prefix for 6to4 Relay Routers" [RFC3068] has been in "An Anycast Prefix for 6to4 Relay Routers" [RFC3068] has been
shown to have severe practical problems when used in the Internet. shown to have severe practical problems when used in the Internet.
This document requests that RFC3056 and RFC3068 be moved to Historic This document requests that RFC3056 and RFC3068 be moved to Historic
status as defined in section 4.2.4 [RFC2026]. status as defined in section 4.2.4 [RFC2026].
6to4 was designed to help transitioning the Internet from IPv4 to 6to4 was designed to help transition the Internet from IPv4 to IPv6.
IPv6. It has been a good mechanism for experimenting with IPv6, but It has been a good mechanism for experimenting with IPv6, but because
because of the high failure rates seen with 6to4 [HUSTON], end users of the high failure rates seen with 6to4 [HUSTON], end users may end
may end up disabling IPv6 on hosts, and content providers are up disabling IPv6 on hosts, and content providers are reluctant to
reluctant to make content available over IPv6. make content available over IPv6.
[I-D.ietf-v6ops-6to4-advisory] analyses the known operational issues [I-D.ietf-v6ops-6to4-advisory] analyses the known operational issues
and describes a set of suggestions to improve 6to4 reliability, given and describes a set of suggestions to improve 6to4 reliability, given
the widespread presence of hosts and customer premises equipment that the widespread presence of hosts and customer premises equipment that
support it. support it.
The IETF sees no evolutionary future for the mechanism and it is not The IETF sees no evolutionary future for the mechanism and it is not
recommended to include this mechanism in new implementations. recommended to include this mechanism in new implementations.
6rd [RFC5969] utilizes the same encapsulation and base mechanism as IPv6 Rapid Deployment on IPv4 Infrastructures (6rd) [RFC5969]
6to4, and could be viewed as a superset of 6to4 (6to4 could be utilizes the same encapsulation and base mechanism as 6to4, and could
achieved by setting the 6rd prefix to 2002::/16). However, the be viewed as a superset of 6to4 (6to4 could be achieved by setting
deployment model is such that 6rd can avoid the problems described the 6rd prefix to 2002::/16). However, the deployment model is such
here. In this sense, 6rd can be viewed as superseding 6to4 as that 6rd can avoid the problems described here. In this sense, 6rd
described in section 4.2.4 of [RFC2026] can be viewed as superseding 6to4 as described in section 4.2.4 of
[RFC2026]
2. Conventions 2. Conventions
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 RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
3. 6to4 operational problems 3. 6to4 operational problems
6to4 is a mechanism designed to allow isolated IPv6 islands to reach 6to4 is a mechanism designed to allow isolated IPv6 islands to reach
skipping to change at page 3, line 25 skipping to change at page 3, line 27
router. It is expected that traffic will use different relays in the router. It is expected that traffic will use different relays in the
forward and reverse direction. RFC3068 adds an extension that allows forward and reverse direction. RFC3068 adds an extension that allows
the use of a well known IPv4 anycast address to reach the nearest the use of a well known IPv4 anycast address to reach the nearest
6to4 relay in the forward direction. 6to4 relay in the forward direction.
One model of 6to4 deployment as described in section 5.2, RFC3056, One model of 6to4 deployment as described in section 5.2, RFC3056,
suggests that a 6to4 router should have a set of managed connections suggests that a 6to4 router should have a set of managed connections
(via BGP connections) to a set of 6to4 relay routers. While this (via BGP connections) to a set of 6to4 relay routers. While this
makes the forward path more controlled, it does not guarantee a makes the forward path more controlled, it does not guarantee a
functional reverse path. In any case this model has the same functional reverse path. In any case this model has the same
operational burden has manually configured tunnels and has seen no operational burden as manually configured tunnels and has seen no
deployment in the public Internet. deployment in the public Internet.
List of some of the known issues with 6to4: List of some of the known issues with 6to4:
o Use of relays. 6to4 depends on an unknown third- party to operate o Use of relays. 6to4 depends on an unknown third- party to operate
the relays between the 6to4 cloud and the native IPv6 Internet. the relays between the 6to4 cloud and the native IPv6 Internet.
o The placement of the relay can lead to increased latency, and in o The placement of the relay can lead to increased latency, and in
the case the relay is overloaded packet loss. the case the relay is overloaded, packet loss.
o There is generally no customer relationship or even a way for the o There is generally no customer relationship between the end-user
end-user to know who the relay operator is, so no support is and the relay operator, or even a way for the end-user to know who
possible. the relay operator is, so no support is possible.
o In case of the reverse path 6to4 relay and the anycast forward o A 6to4 relay for the reverse path and an anycast 6to4 relay used
6to4 relay, these have to be open for any address. Only limited for the forward path, are openly accessible, limited only by the
by the scope of the routing advertisement. 6to4 relays can be used scope of routing. 6to4 relays can be used to anonymize traffic and
to anonymize traffic and inject attacks into IPv6 that are very inject attacks into IPv6 that are very difficult to trace.
difficult to trace. o 6to4 may silently discard traffic in the case where protocol (41)
o 6to4 may black hole traffic in the case where protocol (41) is is blocked in intermediate firewalls. Even if a firewall sent an
blocked in intermediate firewalls. Even if a firewall sent an
ICMP message unreachable back, an IPv4 ICMP message rarely ICMP message unreachable back, an IPv4 ICMP message rarely
contains enough of the original IPv6 packet so that it can be contains enough of the original IPv6 packet so that it can be
relayed back to the IPv6 sender. That makes this problem hard to relayed back to the IPv6 sender. That makes this problem hard to
detect and react upon by the sender of the packet. detect and react upon by the sender of the packet.
o As 6to4 tunnels across the Internet, the IPv4 addresses used must o As 6to4 tunnels across the Internet, the IPv4 addresses used must
be globally reachable. RFC3056 states that a private address be globally reachable. RFC3056 states that a private address
[RFC1918] MUST NOT be used. 6to4 will not work in networks that [RFC1918] MUST NOT be used. 6to4 will not work in networks that
employ other addresses with limited topological span. employ other addresses with limited topological span.
4. Deprecation 4. Deprecation
This document formally deprecates the 6to4 transition mechanism and This document formally deprecates the 6to4 transition mechanism and
the IPv6 6to4 prefix defined in [RFC3056], i.e., 2002::/16. The the IPv6 6to4 prefix defined in [RFC3056], i.e., 2002::/16. The
prefix MUST NOT be reassigned for other use except by a future IETF prefix MUST NOT be reassigned for other use except by a future IETF
standards action. standards action.
It is expected that disabling 6to4 in the IPv6 Internet will take Disabling 6to4 in the IPv6 Internet will take some time. The initial
some time. The initial approach is to make the 6to4 a service of approach is to make 6to4 a service of "last resort" in host
"last resort" in host implementations, ensure that the 6to4 service implementations, ensure that the 6to4 service is disabled by default
is disabled by default in 6to4 routers, and deploy native IPv6 in 6to4 routers, and deploy native IPv6 services. In order to limit
service. In order to limit the impact of end-users, it is the impact of end-users, it is recommended that operators retain
recommended that operators retain their existing 6to4 relay routers their existing 6to4 relay routers and follow the recommendations
and follow the recommendations found in found in [I-D.ietf-v6ops-6to4-advisory]. When traffic levels
[I-D.ietf-v6ops-6to4-advisory]. When traffic levels diminish, these diminish, these routers can be decommissioned.
routers can be decommissioned.
1. IPv6 nodes SHOULD treat 6to4 as a service of "last resort" as IPv6 nodes SHOULD treat 6to4 as a service of "last resort" as
recommended in [I-D.ietf-6man-rfc3484-revise] recommended in [I-D.ietf-6man-rfc3484-revise]
2. Implementations capable of acting as 6to4 routers SHOULD NOT
enable 6to4 without explicit user configuration. In particular, Implementations capable of acting as 6to4 routers SHOULD NOT enable
enabling IPv6 forwarding on a device, SHOULD NOT automatically 6to4 without explicit user configuration. In particular, enabling
enable 6to4. IPv6 forwarding on a device, SHOULD NOT automatically enable 6to4.
Existing implementations and deployments MAY continue to use 6to4. Existing implementations and deployments MAY continue to use 6to4.
The references to 6to4 should be removed as soon as practical from The references to 6to4 should be removed as soon as practical from
the revision of the Special-Use IPv6 Addresses [RFC5156]. the revision of the Special-Use IPv6 Addresses [RFC5156].
The references to the 6to4 relay anycast addresses (192.88.99.0/24)
should be removed as soon as practical from the revision of the
Special Use IPv4 addresses [RFC5735].
Incidental references to 6to4 should be removed from other IETF Incidental references to 6to4 should be removed from other IETF
documents if and when they are updated. These documents include documents if and when they are updated. These documents include
RFC3162, RFC3178, RFC3790, RFC4191, RFC4213, RFC4389, RFC4779, RFC3162, RFC3178, RFC3790, RFC4191, RFC4213, RFC4389, RFC4779,
RFC4852, RFC4891, RFC4903, RFC5157, RFC5245, RFC5375, RFC5971, and RFC4852, RFC4891, RFC4903, RFC5157, RFC5245, RFC5375, RFC5971, and
RFC6071. RFC6071.
5. IANA Considerations 5. IANA Considerations
IANA is requested to mark the 2002::/16 prefix as "deprecated", IANA is requested to mark the 2002::/16 prefix as "deprecated",
pointing to this document. Reassignment of the prefix for any usage pointing to this document. Reassignment of the prefix for any usage
requires justification via an IETF Standards Action [RFC5226]. requires justification via an IETF Standards Action [RFC5226].
IANA is requested to mark the 2.0.0.2.ip6.arpa domain [RFC5158] as The delegation of the 2.0.0.2.ip6.arpa domain [RFC5158] should be
"deprecated", pointing to this document. Redelegation of the domain left in place. Redelegation of the domain for any usage requires
for any usage requires justification via an IETF Standards Action justification via an IETF Standards Action [RFC5226].
[RFC5226].
IANA is requested to mark the 192.88.99.0/24 prefix [RFC3068] as IANA is requested to mark the 192.88.99.0/24 prefix [RFC3068] as
"deprecated", pointing to this document. Redelegation of the domain "deprecated", pointing to this document. Redelegation of the domain
for any usage requires justification via an IETF Standards Action for any usage requires justification via an IETF Standards Action
[RFC5226]. [RFC5226].
6. Security Considerations 6. Security Considerations
There are no new security considerations pertaining to this document. There are no new security considerations pertaining to this document.
General security issues with tunnels are listed in General security issues with tunnels are listed in
[I-D.ietf-v6ops-tunnel-security-concerns] and more specifically to [I-D.ietf-v6ops-tunnel-security-concerns] and more specifically to
6to4 in [RFC3964] and [I-D.ietf-v6ops-tunnel-loops]. 6to4 in [RFC3964] and [I-D.ietf-v6ops-tunnel-loops].
7. Acknowledgements 7. Acknowledgements
The authors would like to acknowledge Tore Anderson, Dmitry Anipko, The authors would like to acknowledge Tore Anderson, Dmitry Anipko,
Jack Bates, Cameron Byrne, Gert Doering, Ray Hunter, Joel Jaeggli, Jack Bates, Cameron Byrne, Ben Campbell, Gert Doering, Ray Hunter,
Kurt Erik Lindqvist, Jason Livingood, Keith Moore, Tom Petch, Daniel Joel Jaeggli, Kurt Erik Lindqvist, Jason Livingood, Keith Moore, Tom
Roesen and Mark Townsley, James Woodyatt, for their contributions and Petch, Daniel Roesen and Mark Townsley, James Woodyatt, for their
discussions on this topic. contributions and discussions on this topic.
Special thanks go to Fred Baker, Geoff Huston, Brian Carpenter, and Special thanks go to Fred Baker, Geoff Huston, Brian Carpenter, and
Wes George for their significant contributions. Wes George for their significant contributions.
Many thanks to Gunter Van de Velde for documenting the harm caused by Many thanks to Gunter Van de Velde for documenting the harm caused by
non-managed tunnels and to stimulate the creation of this document. non-managed tunnels and to stimulate the creation of this document.
8. References 8. References
8.1. Normative References 8.1. Normative References
skipping to change at page 6, line 7 skipping to change at page 6, line 12
[RFC3068] Huitema, C., "An Anycast Prefix for 6to4 Relay Routers", [RFC3068] Huitema, C., "An Anycast Prefix for 6to4 Relay Routers",
RFC 3068, June 2001. RFC 3068, June 2001.
[RFC5156] Blanchet, M., "Special-Use IPv6 Addresses", RFC 5156, [RFC5156] Blanchet, M., "Special-Use IPv6 Addresses", RFC 5156,
April 2008. April 2008.
[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", BCP 26, RFC 5226, IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008. May 2008.
[RFC5735] Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
BCP 153, RFC 5735, January 2010.
8.2. Informative References 8.2. Informative References
[HUSTON] Huston, "Flailing IPv6", December 2010, [HUSTON] Huston, "Flailing IPv6", December 2010,
<http://www.potaroo.net/ispcol/2010-12/6to4fail.html>. <http://www.potaroo.net/ispcol/2010-12/6to4fail.html>.
[I-D.ietf-6man-rfc3484-revise] [I-D.ietf-6man-rfc3484-revise]
Matsumoto, A., Kato, J., and T. Fujisaki, "Update to RFC Matsumoto, A., Kato, J., and T. Fujisaki, "Update to RFC
3484 Default Address Selection for IPv6", 3484 Default Address Selection for IPv6",
draft-ietf-6man-rfc3484-revise-02 (work in progress), draft-ietf-6man-rfc3484-revise-03 (work in progress),
March 2011. June 2011.
[I-D.ietf-v6ops-6to4-advisory] [I-D.ietf-v6ops-6to4-advisory]
Carpenter, B., "Advisory Guidelines for 6to4 Deployment", Carpenter, B., "Advisory Guidelines for 6to4 Deployment",
draft-ietf-v6ops-6to4-advisory-01 (work in progress), draft-ietf-v6ops-6to4-advisory-02 (work in progress),
April 2011. June 2011.
[I-D.ietf-v6ops-tunnel-loops] [I-D.ietf-v6ops-tunnel-loops]
Nakibly, G. and F. Templin, "Routing Loop Attack using Nakibly, G. and F. Templin, "Routing Loop Attack using
IPv6 Automatic Tunnels: Problem Statement and Proposed IPv6 Automatic Tunnels: Problem Statement and Proposed
Mitigations", draft-ietf-v6ops-tunnel-loops-07 (work in Mitigations", draft-ietf-v6ops-tunnel-loops-07 (work in
progress), May 2011. progress), May 2011.
[I-D.ietf-v6ops-tunnel-security-concerns] [I-D.ietf-v6ops-tunnel-security-concerns]
Krishnan, S., Thaler, D., and J. Hoagland, "Security Krishnan, S., Thaler, D., and J. Hoagland, "Security
Concerns With IP Tunneling", Concerns With IP Tunneling",
 End of changes. 17 change blocks. 
55 lines changed or deleted 61 lines changed or added

This html diff was produced by rfcdiff 1.41. The latest version is available from http://tools.ietf.org/tools/rfcdiff/