draft-ietf-v6ops-vlan-usage-00.txt   draft-ietf-v6ops-vlan-usage-01.txt 
IPv6 Operations T. Chown IPv6 Operations T. Chown
Internet-Draft University of Southampton Internet-Draft University of Southampton
Expires: January 12, 2006 July 11, 2005 Expires: September 7, 2006 March 6, 2006
Use of VLANs for IPv4-IPv6 Coexistence in Enterprise Networks Use of VLANs for IPv4-IPv6 Coexistence in Enterprise Networks
draft-ietf-v6ops-vlan-usage-00 draft-ietf-v6ops-vlan-usage-01
Status of this Memo Status of this Memo
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Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2005). Copyright (C) The Internet Society (2006).
Abstract Abstract
Ethernet VLANs are quite commonly used in enterprise networks for the Ethernet VLANs are quite commonly used in enterprise networks for the
purposes of traffic segregation. This document describes how such purposes of traffic segregation. This document describes how such
VLANs can be readily used to deploy IPv6 networking in an enterprise, VLANs can be readily used to deploy IPv6 networking in an enterprise,
which focuses on the scenario of early deployment prior to which focuses on the scenario of early deployment prior to
availability of IPv6-capable switch-router equipment. In this method availability of IPv6-capable switch-router equipment. In this method
IPv6 may be routed in parallel with the existing IPv4 in the IPv6 may be routed in parallel with the existing IPv4 in the
enterprise and delivered at Layer 2 via VLAN technology. The IPv6 enterprise and delivered at Layer 2 via VLAN technology. The IPv6
connectivity to the enterprise may or may not enter the site via the connectivity to the enterprise may or may not enter the site via the
same physical link. same physical link.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Enabling IPv6 per link . . . . . . . . . . . . . . . . . . . . 4 2. Enabling IPv6 per link . . . . . . . . . . . . . . . . . . . . 4
2.1 IPv6 routing over VLANs . . . . . . . . . . . . . . . . . 4 2.1. IPv6 routing over VLANs . . . . . . . . . . . . . . . . . 4
2.2 One VLAN per router interface . . . . . . . . . . . . . . 5 2.2. One VLAN per router interface . . . . . . . . . . . . . . 5
2.3 Collapsed VLANs on a single interface . . . . . . . . . . 5 2.3. Collapsed VLANs on a single interface . . . . . . . . . . 5
2.4 Congruent IPv4 and IPv6 Subnets . . . . . . . . . . . . . 5 2.4. Congruent IPv4 and IPv6 Subnets . . . . . . . . . . . . . 6
2.5 IPv6 Addressing . . . . . . . . . . . . . . . . . . . . . 6 2.5. IPv6 Addressing . . . . . . . . . . . . . . . . . . . . . 6
2.6 Final IPv6 Deployment . . . . . . . . . . . . . . . . . . 6 2.6. Final IPv6 Deployment . . . . . . . . . . . . . . . . . . 6
3. Example VLAN topology . . . . . . . . . . . . . . . . . . . . 7 3. Example VLAN topology . . . . . . . . . . . . . . . . . . . . 7
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 8 5. Security Considerations . . . . . . . . . . . . . . . . . . . 8
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 8
7. Informative References . . . . . . . . . . . . . . . . . . . . 9 7. Informative References . . . . . . . . . . . . . . . . . . . . 9
Author's Address . . . . . . . . . . . . . . . . . . . . . . . 9 Appendix A. Appendix: Configuration example . . . . . . . . . . . 9
A. Appendix: Configuration example . . . . . . . . . . . . . . . 9 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . . . 13
1. Introduction 1. Introduction
Ethernet VLANs are quite commonly used in enterprise networks for the Ethernet VLANs are quite commonly used in enterprise networks for the
purposes of traffic segregation. This document describes how such purposes of traffic segregation. This document describes how such
VLANs can be readily used to deploy IPv6 networking in an enterprise, VLANs can be readily used to deploy IPv6 networking in an enterprise,
including the scenario of early deployment prior to availability of including the scenario of early deployment prior to availability of
IPv6-capable switch-router equipment, where IPv6 may be routed in IPv6-capable switch-router equipment, where IPv6 may be routed in
parallel with the existing IPv4 in the enterprise and delivered to parallel with the existing IPv4 in the enterprise and delivered to
the desired LANs via VLAN technology. the desired LANs via VLAN technology.
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parallel IPv6 routing infrastructure (which is likely to be a parallel IPv6 routing infrastructure (which is likely to be a
different platform to the site's main infrastructure equipment, i.e. different platform to the site's main infrastructure equipment, i.e.
one that supports IPv6 where the existing equipment does not), and one that supports IPv6 where the existing equipment does not), and
then using VLAN technology to "overlay" IPv6 links onto existing IPv4 then using VLAN technology to "overlay" IPv6 links onto existing IPv4
links. This can be achieved without needing any changes to the IPv4 links. This can be achieved without needing any changes to the IPv4
configuration. The VLANs don't need to differentiate between IPv4 configuration. The VLANs don't need to differentiate between IPv4
and IPv6; the deployment is just dual stack, as Ethernet is without and IPv6; the deployment is just dual stack, as Ethernet is without
VLANs. VLANs.
The IPv4 default route to the VLAN is provided by one (IPv4) router, The IPv4 default route to the VLAN is provided by one (IPv4) router,
while the IPv6 default route to the VLAN is provided a different while the IPv6 default route to the VLAN is provided by a different
(IPv6) router. The IPv6 router can provide native IPv6 connectivity (IPv6) router. The IPv6 router can provide native IPv6 connectivity
to the whole site with just a single physical interface, thanks to to the whole site with just a single physical interface, thanks to
VLAN tagging and trunking, as described below. VLAN tagging and trunking, as described below.
The IPv6 connectivity to the enterprise may or may not enter the site The IPv6 connectivity to the enterprise may or may not enter the site
via the same physical link as the IPv4 traffic, and may be native or via the same physical link as the IPv4 traffic, and may be native or
tunneled from the external provider to the IPv6 routing equipment. tunneled from the external provider to the IPv6 routing equipment.
This VLAN usage is a solution adopted by a number of sites already, This VLAN usage is a solution adopted by a number of sites already,
and is referenced in our Campus Network IPv6 Transition [2] text. including that of the author.
It should be noted that a parallel infrastructure will require It should be noted that a parallel infrastructure will require
additional infrastructure and thus cost, and will often require a additional infrastructure and thus cost, and will often require a
separate link into the site (from an IPv6 provider), quite possibly separate link into the site (from an IPv6 provider), quite possibly
tunneled, that will require the site's security policy to be applied tunneled, that will require the site's security policy to be applied
(e.g. firewalling, and intrusion detection). For sites who believe (e.g. firewalling, and intrusion detection). For sites that believe
early adoption of IPv6 is important, that price is one they may be early adoption of IPv6 is important, that price is one they may be
quite willing to pay. However, this document focuses on the quite willing to pay. However, this document focuses on the
technical issues of VLAN usage in such a scenario. technical issues of VLAN usage in such a scenario.
2. Enabling IPv6 per link 2. Enabling IPv6 per link
The precise method by which IPv6 would be "injected" into the The precise method by which IPv6 would be "injected" into the
existing IPv4 network is deployment specific. For example, perhaps a existing IPv4 network is deployment specific. For example, perhaps a
site has an IPv4-only router, connected to an Ethernet switch that site has an IPv4-only router, connected to an Ethernet switch that
supports VLANs, and a number of hosts connected to that VLAN. Let's supports VLANs, and a number of hosts connected to that VLAN. Let's
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The simplest approach would be to connect an IPv6 router with one The simplest approach would be to connect an IPv6 router with one
interface to an ethernet switch, and connect that switch to other interface to an ethernet switch, and connect that switch to other
switches, and then use VLAN tags between the switches and the IPv6 switches, and then use VLAN tags between the switches and the IPv6
router to "reach" all the IPv4-only subnets from the IPv6 router. router to "reach" all the IPv4-only subnets from the IPv6 router.
Thus the general principle is that the IPv6 router device (e.g. Thus the general principle is that the IPv6 router device (e.g.
performing IPv6 Router Advertisements [1] in the case of stateless performing IPv6 Router Advertisements [1] in the case of stateless
autoconfiguration) is connected to the target link through the use of autoconfiguration) is connected to the target link through the use of
VLAN capable Layer 2 equipment. VLAN capable Layer 2 equipment.
2.1 IPv6 routing over VLANs 2.1. IPv6 routing over VLANs
In a typical scenario where connectivity is to be offered to a number In a typical scenario where connectivity is to be offered to a number
of existing IPv6 internal subnets, one IPv6 router could be deployed, of existing IPv6 internal subnets, one IPv6 router could be deployed,
with both an external interface and one or more internal interfaces. with both an external interface and one or more internal interfaces.
The external interface connects to the wider IPv6 internet, and may The external interface connects to the wider IPv6 internet, and may
be dual-stack if some tunnel mechanism is used for external be dual-stack if some tunnel mechanism is used for external
connectivity, or IPv6-only if a native external connection is connectivity, or IPv6-only if a native external connection is
available. available.
The internal interface(s) can be connected directly to a VLAN-capable The internal interface(s) can be connected directly to a VLAN-capable
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from the internal router interface based on the target IPv6 link from the internal router interface based on the target IPv6 link
prefix. The VLAN-tagged traffic is then transported across the prefix. The VLAN-tagged traffic is then transported across the
internal VLAN-capable site infrastructure to the target IPv6 links internal VLAN-capable site infrastructure to the target IPv6 links
(which may be dispersed widely across the site network). (which may be dispersed widely across the site network).
Where the IPv6 router is unable to VLAN-tag the packets, a protocol- Where the IPv6 router is unable to VLAN-tag the packets, a protocol-
based VLAN can be created on the VLAN-capable device connected to the based VLAN can be created on the VLAN-capable device connected to the
IPv6 router, causing IPv6 traffic to be tagged and then redistributed IPv6 router, causing IPv6 traffic to be tagged and then redistributed
on (congruent) IPv4 subnet links that lie in the same VLAN. on (congruent) IPv4 subnet links that lie in the same VLAN.
2.2 One VLAN per router interface 2.2. One VLAN per router interface
The VLAN marking may be done in different ways. Some sites may The VLAN marking may be done in different ways. Some sites may
prefer to use one router interface per VLAN, e.g. if there are three prefer to use one router interface per VLAN, e.g. if there are three
internal IPv6 links, a BSD-based IPv6 router with four Ethernet ports internal IPv6 links, a standard PC-based IPv6 router with four
could be used, one for the external link and three for the internal Ethernet ports could be used, one for the external link and three for
links. In such a case one switch port would be needed per link, to the internal links. In such a case one switch port would be needed
receive the connectivity from each router port. per link, to receive the connectivity from each router port.
In such a deployment, the IPv6 routing could be cascaded through In such a deployment, the IPv6 routing could be cascaded through
lower tier internal IPv6-only routers. Here, the internal facing lower tier internal IPv6-only routers. Here, the internal facing
ports on the IPv6 edge router may feed other IPv6 routers over IPv6- ports on the IPv6 edge router may feed other IPv6 routers over IPv6-
only links which in turn inject the IPv6 connectivity (the /64 size only links which in turn inject the IPv6 connectivity (the stub links
links and associated Router Advertisements) into the VLANs. using 64 bit subnet prefixes and associated Router Advertisements)
into the VLANs.
2.3 Collapsed VLANs on a single interface 2.3. Collapsed VLANs on a single interface
Using multiple IPv6 routers and one port per IPv6 link (i.e. VLAN) Using multiple IPv6 routers and one port per IPv6 link (i.e. VLAN)
may be unnecessary. Many devices now support VLAN tagging based on may be unnecessary. Many devices now support VLAN tagging based on
virtual interfaces such that multiple IPv6 VLANs could be assigned virtual interfaces such that multiple IPv6 VLANs could be assigned
(trunked) from one physical router interface port. Thus it is (trunked) from one physical router interface port. Thus it is
possible to use just one router interface for "aggregated" VLAN possible to use just one router interface for "aggregated" VLAN
trunking from a switch. This is a far more interesting case for a trunking from a switch. This is a far more interesting case for a
site planning the introduction of IPv6 to (part of) its site network. site planning the introduction of IPv6 to (part of) its site network.
This approach is viable while IPv6 traffic load is light. As traffic This approach is viable while the IPv6 traffic load is light. As
volume grows, the single collapsed interface could be extended to traffic volume grows, the single collapsed interface could be
utilise two or more physical ports, where the capacity of the IPv6 extended to utilise two or more physical ports, where the capacity of
router device allows it. the IPv6 router device allows it.
2.4 Congruent IPv4 and IPv6 Subnets 2.4. Congruent IPv4 and IPv6 Subnets
Such a VLAN-based technique can be used to deploy IPv6-only VLANs in Such a VLAN-based technique can be used to deploy IPv6-only VLANs in
an enterprise network. However most enterprises will be interested an enterprise network. However most enterprises will be interested
in dual-stack IPv4-IPv6 networking. in dual-stack IPv4-IPv6 networking.
In such a case the IPv6 connectivity may be injected into the In such a case the IPv6 connectivity may be injected into the
existing IPv4 VLANs, such that the IPv4 and IPv6 subnets are existing IPv4 VLANs, such that the IPv4 and IPv6 subnets are
congruent (i.e. they coincide exactly when superimposed). Such a congruent (i.e. they coincide exactly when superimposed). Such a
method may have desirable administrative properties, e.g. the devices method may have desirable administrative properties, e.g. the devices
in each IPv4 subnet will be in the same IPv6 subnets also. This is in each IPv4 subnet will be in the same IPv6 subnets also. This is
the method being used in our Campus Network IPv6 Transition [2] text. the method used at the author's site.
Further, IPv6-only devices may be gradually added into the subnet Further, IPv6-only devices may be gradually added into the subnet
without any need to resize the IPv6 subnet (which may hold in effect without any need to resize the IPv6 subnet (which may hold in effect
an infinite number of hosts in a /64 in contrast to IPv4 where the an infinite number of hosts in a /64 in contrast to IPv4 where the
subnet size is often relatively limited, or kept to a minimum subnet size is often relatively limited, or kept to a minimum
possible due to address space usage concerns). The lack of possible due to address space usage concerns). The lack of
requirement to periodically resize an IPv6 subnet is a useful requirement to periodically resize an IPv6 subnet is a useful
administrative advantage for IPv6. administrative advantage for IPv6.
2.5 IPv6 Addressing 2.5. IPv6 Addressing
One site using this VLAN technique has chosen to number its IPv6 One site using this VLAN technique has chosen to number its IPv6
links with the format [Site IPv6 prefix]:[VLAN ID]::/64. This is not links with the format [Site IPv6 prefix]:[VLAN ID]::/64. The VLAN
a recommended addressing plan, but some sites may wish to consider tag is 16 bits so this can work with a typical maximum 48 bit site
its usage. prefix. This is not a recommended addressing plan, but some sites
may wish to consider its usage.
2.6 Final IPv6 Deployment 2.6. Final IPv6 Deployment
The VLAN technique for IPv6 deployment offers a more structured The VLAN technique for IPv6 deployment offers a more structured
alternative to opportunistic per-host intra-site tunnelling methods alternative to opportunistic per-host intra-site tunnelling methods
such as ISATAP [3]. It has the ability to offer a simple yet such as ISATAP [2]. It has the ability to offer a simple yet
efficient method for early IPv6 deployment to an enterprise site. efficient method for early IPv6 deployment to an enterprise site.
When the site acquires IPv6-capable switch-router equipment, the When the site acquires IPv6-capable switch-router equipment, the
VLAN-based mathod can still be used for delivery of IPv6 links to VLAN-based mathod can still be used for delivery of IPv6 links to
physical switch interfaces, just as it is commonly today for IPv4 physical switch interfaces, just as it is commonly today for IPv4
subnets, but with a common routing infrastructure. subnets, but with a common routing infrastructure.
3. Example VLAN topology 3. Example VLAN topology
The following figure shows how a VLAN topology may be used to The following figure shows how a VLAN topology may be used to
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particular Pekka Savola (CSC/FUNET), but also including Janos Mohacsi particular Pekka Savola (CSC/FUNET), but also including Janos Mohacsi
(Hungarnet), Martin Dunmore and Chris Edwards (Lancaster University), (Hungarnet), Martin Dunmore and Chris Edwards (Lancaster University),
Christian Strauf (JOIN Project, University of Muenster) and Stig Christian Strauf (JOIN Project, University of Muenster) and Stig
Venaas (UNINETT). Venaas (UNINETT).
7. Informative References 7. Informative References
[1] Narten, T., Nordmark, E., and W. Simpson, "Neighbor Discovery [1] Narten, T., Nordmark, E., and W. Simpson, "Neighbor Discovery
for IP Version 6 (IPv6)", RFC 2461, December 1998. for IP Version 6 (IPv6)", RFC 2461, December 1998.
[2] Chown, T., "IPv6 Campus Transition Scenario Description and [2] Templin, F., Gleeson, T., Talwar, M., and D. Thaler, "Intra-Site
Analysis", draft-chown-v6ops-campus-transition-01 (work in Automatic Tunnel Addressing Protocol (ISATAP)", RFC 4214,
progress), October 2004. October 2005.
[3] Templin, F., Gleeson, T., Talwar, M., and D. Thaler, "Intra-Site
Automatic Tunnel Addressing Protocol (ISATAP)",
draft-ietf-ngtrans-isatap-24 (work in progress), January 2005.
Author's Address
Tim Chown
University of Southampton
Southampton, Hampshire SO17 1BJ
United Kingdom
Email: tjc@ecs.soton.ac.uk
Appendix A. Appendix: Configuration example Appendix A. Appendix: Configuration example
In this section we describe a configuration example for BSD to deploy In this section we describe a configuration example for using a
IPv6 networking across a number of IPv6 links on an enterprise (in computer running the FreeBSD variant of the Berkeley Software
this case, six links), for a scenario similar to the one described Distribution (BSD) operating system as a router to deploy IPv6
above. Here the precise configuration may of course vary depending networking across a number of IPv6 links on an enterprise (in this
on the existing site VLAN deployment. This section highlights that case, six links), for a scenario similar to the one described above.
the VLAN configuration must be manually configured; the support is Here the precise configuration may of course vary depending on the
not "automatic". existing site VLAN deployment. This section highlights that the VLAN
configuration must be manually configured; the support is not
"automatic".
In this example, the configuration is for an IPv6 BSD router In this example, the configuration is for an IPv6 BSD router
connected directly to a site's external IPv6 access router. The BSD connected directly to a site's external IPv6 access router. The BSD
router has one interface (dc0) towards the site IPv6access router, router has one interface (dc0) towards the site IPv6access router,
and three interfaces (dc1, dc2, dc3) over which the internal routing and three interfaces (dc1, dc2, dc3) over which the internal routing
is performed (the number of interfaces can be varied, three are used is performed (the number of interfaces can be varied, three are used
here to distribute the traffic load). The IPv6 documentation prefix here to distribute the traffic load). The IPv6 documentation prefix
(2001:db8::/32) is used in the example. (2001:db8::/32) is used in the example.
--- Example IPv6 VLAN configuration, FreeBSD --- --- Example IPv6 VLAN configuration, FreeBSD ---
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ipv6_network_interfaces="vlan0 vlan1 vlan2 vlan3 vlan4 vlan5 vlan6" ipv6_network_interfaces="vlan0 vlan1 vlan2 vlan3 vlan4 vlan5 vlan6"
# Define addresses # Define addresses
ipv6_ifconfig_vlan0="2001:db8:d0:101::2 prefixlen 64" # Uplink ipv6_ifconfig_vlan0="2001:db8:d0:101::2 prefixlen 64" # Uplink
ipv6_ifconfig_vlan1="2001:db8:d0:111::1 prefixlen 64" # Subnet1 ipv6_ifconfig_vlan1="2001:db8:d0:111::1 prefixlen 64" # Subnet1
ipv6_ifconfig_vlan2="2001:db8:d0:112::1 prefixlen 64" # Subnet2 ipv6_ifconfig_vlan2="2001:db8:d0:112::1 prefixlen 64" # Subnet2
ipv6_ifconfig_vlan3="2001:db8:d0:121::1 prefixlen 64" # Subnet3 ipv6_ifconfig_vlan3="2001:db8:d0:121::1 prefixlen 64" # Subnet3
ipv6_ifconfig_vlan4="2001:db8:d0:113::1 prefixlen 64" # Subnet4 ipv6_ifconfig_vlan4="2001:db8:d0:113::1 prefixlen 64" # Subnet4
ipv6_ifconfig_vlan5="2001:db8:d0:114::1 prefixlen 64" # Subnet5 ipv6_ifconfig_vlan5="2001:db8:d0:114::1 prefixlen 64" # Subnet5
ipv6_ifconfig_vlan6="2001:db8:d0:115::1 prefixlen 64" # Subnet6 ipv6_ifconfig_vlan6="2001:db8:d0:115::1 prefixlen 64" # Subnet6
# Router advs # Router advertisements
rtadvd_enable="YES" rtadvd_enable="YES"
rtadvd_interfaces="-s vlan0 vlan1 vlan2 vlan3 vlan4 vlan5 vlan6" rtadvd_interfaces="-s vlan0 vlan1 vlan2 vlan3 vlan4 vlan5 vlan6"
### Routing ### ### Routing ###
# Multicast # Multicast
mroute6d_enable="YES" mroute6d_enable="YES"
mroute6d_program="/sbin/pim6sd" mroute6d_program="/sbin/pim6sd"
# RIP-ng # RIP-ng
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The VLAN IDs need to be managed by the site administrator, but would The VLAN IDs need to be managed by the site administrator, but would
probably already be assigned for existing IPv4 subnets (ones into probably already be assigned for existing IPv4 subnets (ones into
which IPv6 is being introduced). which IPv6 is being introduced).
For a large enterprise, a combination of internal tunnels and VLAN For a large enterprise, a combination of internal tunnels and VLAN
usage could be used; the whole site need not be enabled by VLAN usage could be used; the whole site need not be enabled by VLAN
tagging alone. This choice is one for the site administrator to tagging alone. This choice is one for the site administrator to
make. make.
Author's Address
Tim Chown
University of Southampton
Southampton, Hampshire SO17 1BJ
United Kingdom
Email: tjc@ecs.soton.ac.uk
Intellectual Property Statement Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
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This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement Copyright Statement
Copyright (C) The Internet Society (2005). This document is subject Copyright (C) The Internet Society (2006). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights. except as set forth therein, the authors retain all their rights.
Acknowledgment Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is currently provided by the
Internet Society. Internet Society.
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