From 1920f1b489a54e8ab97a3e24b1bab64831e32b53 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Fri, 26 Apr 2019 17:57:49 +0200 Subject: New upstream version 0.9.2 --- doc/rfc3513.htm | 1579 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1579 insertions(+) create mode 100644 doc/rfc3513.htm (limited to 'doc/rfc3513.htm') diff --git a/doc/rfc3513.htm b/doc/rfc3513.htm new file mode 100644 index 0000000..0b8bfb6 --- /dev/null +++ b/doc/rfc3513.htm @@ -0,0 +1,1579 @@ + + + + + + + + + RFC 3513 Internet Protocol Version 6 (IPv6) Addressing Architecture + + + + + +
+ + +
+[RFCs/IDs] [Plain Text] [From draft-ietf-ipngwg-addr-arch-v3]
+
+Obsoleted by: 4291 PROPOSED STANDARD
+
+
Network Working Group                                          R. Hinden
+Request for Comments: 3513                                         Nokia
+Obsoletes: 2373                                               S. Deering
+Category: Standards Track                                  Cisco Systems
+                                                              April 2003
+
+
+       
Internet Protocol Version 6 (IPv6) Addressing Architecture

+
+Status of this Memo
+
+   This document specifies an Internet standards track protocol for the
+   Internet community, and requests discussion and suggestions for
+   improvements.  Please refer to the current edition of the "Internet
+   Official Protocol Standards" (STD 1) for the standardization state
+   and status of this protocol.  Distribution of this memo is unlimited.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2003).  All Rights Reserved.
+
+Abstract
+
+   This specification defines the addressing architecture of the IP
+   Version 6 (IPv6) protocol.  The document includes the IPv6 addressing
+   model, text representations of IPv6 addresses, definition of IPv6
+   unicast addresses, anycast addresses, and multicast addresses, and an
+   IPv6 node's required addresses.
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+Hinden & Deering            Standards Track                     [Page 1]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+Table of Contents
+
+   1. Introduction.................................................3
+   2. IPv6 Addressing..............................................3
+      2.1 Addressing Model.........................................4
+      2.2 Text Representation of Addresses.........................4
+      2.3 Text Representation of Address Prefixes..................5
+      2.4 Address Type Identification..............................6
+      2.5 Unicast Addresses........................................7
+          2.5.1 Interface Identifiers..............................8
+          2.5.2 The Unspecified Address............................9
+          2.5.3 The Loopback Address...............................9
+          2.5.4 Global Unicast Addresses..........................10
+          2.5.5 IPv6 Addresses with Embedded IPv4 Addresses.......10
+          2.5.6 Local-use IPv6 Unicast Addresses..................11
+      2.6 Anycast Addresses.......................................12
+          2.6.1 Required Anycast Address..........................13
+      2.7 Multicast Addresses.....................................13
+          2.7.1 Pre-Defined Multicast Addresses...................15
+      2.8 A Node's Required Addresses.............................17
+   3. Security Considerations.....................................17
+   4. IANA Considerations.........................................18
+   5. References..................................................19
+      5.1 Normative References....................................19
+      5.2 Informative References..................................19
+   APPENDIX A: Creating Modified EUI-64 format Interface IDs......21
+   APPENDIX B: Changes from RFC-2373..............................24
+   Authors' Addresses.............................................25
+   Full Copyright Statement.......................................26
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+Hinden & Deering            Standards Track                     [Page 2]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+
1.  Introduction

+
+   This specification defines the addressing architecture of the IP
+   Version 6 (IPv6) protocol.  It includes the basic formats for the
+   various types of IPv6 addresses (unicast, anycast, and multicast).
+
+   The authors would like to acknowledge the contributions of Paul
+   Francis, Scott Bradner, Jim Bound, Brian Carpenter, Matt Crawford,
+   Deborah Estrin, Roger Fajman, Bob Fink, Peter Ford, Bob Gilligan,
+   Dimitry Haskin, Tom Harsch, Christian Huitema, Tony Li, Greg
+   Minshall, Thomas Narten, Erik Nordmark, Yakov Rekhter, Bill Simpson,
+   Sue Thomson, Markku Savela, and Larry Masinter.
+
+
2. IPv6 Addressing

+
+   IPv6 addresses are 128-bit identifiers for interfaces and sets of
+   interfaces (where "interface" is as defined in section 2 of [IPV6]).
+   There are three types of addresses:
+
+   Unicast:   An identifier for a single interface.  A packet sent to a
+              unicast address is delivered to the interface identified
+              by that address.
+
+   Anycast:   An identifier for a set of interfaces (typically belonging
+              to different nodes).  A packet sent to an anycast address
+              is delivered to one of the interfaces identified by that
+              address (the "nearest" one, according to the routing
+              protocols' measure of distance).
+
+   Multicast: An identifier for a set of interfaces (typically belonging
+              to different nodes).  A packet sent to a multicast address
+              is delivered to all interfaces identified by that address.
+
+   There are no broadcast addresses in IPv6, their function being
+   superseded by multicast addresses.
+
+   In this document, fields in addresses are given a specific name, for
+   example "subnet".  When this name is used with the term "ID" for
+   identifier after the name (e.g., "subnet ID"), it refers to the
+   contents of the named field.  When it is used with the term "prefix"
+   (e.g., "subnet prefix") it refers to all of the address from the left
+   up to and including this field.
+
+   In IPv6, all zeros and all ones are legal values for any field,
+   unless specifically excluded.  Specifically, prefixes may contain, or
+   end with, zero-valued fields.
+
+
+
+
+
+Hinden & Deering            Standards Track                     [Page 3]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+
2.1 Addressing Model

+
+   IPv6 addresses of all types are assigned to interfaces, not nodes.
+   An IPv6 unicast address refers to a single interface.  Since each
+   interface belongs to a single node, any of that node's interfaces'
+   unicast addresses may be used as an identifier for the node.
+
+   All interfaces are required to have at least one link-local unicast
+   address (see section 2.8 for additional required addresses).  A
+   single interface may also have multiple IPv6 addresses of any type
+   (unicast, anycast, and multicast) or scope.  Unicast addresses with
+   scope greater than link-scope are not needed for interfaces that are
+   not used as the origin or destination of any IPv6 packets to or from
+   non-neighbors.  This is sometimes convenient for point-to-point
+   interfaces.  There is one exception to this addressing model:
+
+      A unicast address or a set of unicast addresses may be assigned to
+      multiple physical interfaces if the implementation treats the
+      multiple physical interfaces as one interface when presenting it
+      to the internet layer.  This is useful for load-sharing over
+      multiple physical interfaces.
+
+   Currently IPv6 continues the IPv4 model that a subnet prefix is
+   associated with one link.  Multiple subnet prefixes may be assigned
+   to the same link.
+
+
2.2 Text Representation of Addresses

+
+   There are three conventional forms for representing IPv6 addresses as
+   text strings:
+
+   1. The preferred form is x:x:x:x:x:x:x:x, where the 'x's are the
+      hexadecimal values of the eight 16-bit pieces of the address.
+
+      Examples:
+
+         FEDC:BA98:7654:3210:FEDC:BA98:7654:3210
+
+         1080:0:0:0:8:800:200C:417A
+
+      Note that it is not necessary to write the leading zeros in an
+      individual field, but there must be at least one numeral in every
+      field (except for the case described in 2.).
+
+   2. Due to some methods of allocating certain styles of IPv6
+      addresses, it will be common for addresses to contain long strings
+      of zero bits.  In order to make writing addresses containing zero
+      bits easier a special syntax is available to compress the zeros.
+
+
+
+Hinden & Deering            Standards Track                     [Page 4]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+      The use of "::" indicates one or more groups of 16 bits of zeros.
+      The "::" can only appear once in an address.  The "::" can also be
+      used to compress leading or trailing zeros in an address.
+
+      For example, the following addresses:
+
+         1080:0:0:0:8:800:200C:417A  a unicast address
+         FF01:0:0:0:0:0:0:101        a multicast address
+         0:0:0:0:0:0:0:1             the loopback address
+         0:0:0:0:0:0:0:0             the unspecified addresses
+
+      may be represented as:
+
+         1080::8:800:200C:417A       a unicast address
+         FF01::101                   a multicast address
+         ::1                         the loopback address
+         ::                          the unspecified addresses
+
+   3. An alternative form that is sometimes more convenient when dealing
+      with a mixed environment of IPv4 and IPv6 nodes is
+      x:x:x:x:x:x:d.d.d.d, where the 'x's are the hexadecimal values of
+      the six high-order 16-bit pieces of the address, and the 'd's are
+      the decimal values of the four low-order 8-bit pieces of the
+      address (standard IPv4 representation).  Examples:
+
+         0:0:0:0:0:0:13.1.68.3
+
+         0:0:0:0:0:FFFF:129.144.52.38
+
+      or in compressed form:
+
+         ::13.1.68.3
+
+         ::FFFF:129.144.52.38
+
+
2.3 Text Representation of Address Prefixes

+
+   The text representation of IPv6 address prefixes is similar to the
+   way IPv4 addresses prefixes are written in CIDR notation [CIDR].  An
+   IPv6 address prefix is represented by the notation:
+
+      ipv6-address/prefix-length
+
+   where
+
+      ipv6-address    is an IPv6 address in any of the notations listed
+                      in section 2.2.
+
+
+
+
+Hinden & Deering            Standards Track                     [Page 5]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+      prefix-length   is a decimal value specifying how many of the
+                      leftmost contiguous bits of the address comprise
+                      the prefix.
+
+   For example, the following are legal representations of the 60-bit
+   prefix 12AB00000000CD3 (hexadecimal):
+
+      12AB:0000:0000:CD30:0000:0000:0000:0000/60
+      12AB::CD30:0:0:0:0/60
+      12AB:0:0:CD30::/60
+
+   The following are NOT legal representations of the above prefix:
+
+      12AB:0:0:CD3/60   may drop leading zeros, but not trailing zeros,
+                        within any 16-bit chunk of the address
+
+      12AB::CD30/60     address to left of "/" expands to
+                        12AB:0000:0000:0000:0000:000:0000:CD30
+
+      12AB::CD3/60      address to left of "/" expands to
+                        12AB:0000:0000:0000:0000:000:0000:0CD3
+
+   When writing both a node address and a prefix of that node address
+   (e.g., the node's subnet prefix), the two can combined as follows:
+
+      the node address      12AB:0:0:CD30:123:4567:89AB:CDEF
+      and its subnet number 12AB:0:0:CD30::/60
+
+      can be abbreviated as 12AB:0:0:CD30:123:4567:89AB:CDEF/60
+
+2.4 Address Type Identification
+
+   The type of an IPv6 address is identified by the high-order bits of
+   the address, as follows:
+
+   Address type         Binary prefix        IPv6 notation   Section
+   ------------         -------------        -------------   -------
+   Unspecified          00...0  (128 bits)   ::/128          2.5.2
+   Loopback             00...1  (128 bits)   ::1/128         2.5.3
+   Multicast            11111111             FF00::/8        2.7
+   Link-local unicast   1111111010           FE80::/10       2.5.6
+   Site-local unicast   1111111011           FEC0::/10       2.5.6
+   Global unicast       (everything else)
+
+   Anycast addresses are taken from the unicast address spaces (of any
+   scope) and are not syntactically distinguishable from unicast
+   addresses.
+
+
+
+
+Hinden & Deering            Standards Track                     [Page 6]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   The general format of global unicast addresses is described in
+   section 2.5.4.  Some special-purpose subtypes of global unicast
+   addresses which contain embedded IPv4 addresses (for the purposes of
+   IPv4-IPv6 interoperation) are described in section 2.5.5.
+
+   Future specifications may redefine one or more sub-ranges of the
+   global unicast space for other purposes, but unless and until that
+   happens, implementations must treat all addresses that do not start
+   with any of the above-listed prefixes as global unicast addresses.
+
+
2.5 Unicast Addresses

+
+   IPv6 unicast addresses are aggregable with prefixes of arbitrary
+   bit-length similar to IPv4 addresses under Classless Interdomain
+   Routing.
+
+   There are several types of unicast addresses in IPv6, in particular
+   global unicast, site-local unicast, and link-local unicast.  There
+   are also some special-purpose subtypes of global unicast, such as
+   IPv6 addresses with embedded IPv4 addresses or encoded NSAP
+   addresses.  Additional address types or subtypes can be defined in
+   the future.
+
+   IPv6 nodes may have considerable or little knowledge of the internal
+   structure of the IPv6 address, depending on the role the node plays
+   (for instance, host versus router).  At a minimum, a node may
+   consider that unicast addresses (including its own) have no internal
+   structure:
+
+   |                           128 bits                              |
+   +-----------------------------------------------------------------+
+   |                          node address                           |
+   +-----------------------------------------------------------------+
+
+   A slightly sophisticated host (but still rather simple) may
+   additionally be aware of subnet prefix(es) for the link(s) it is
+   attached to, where different addresses may have different values for
+   n:
+
+   |                         n bits                 |   128-n bits   |
+   +------------------------------------------------+----------------+
+   |                   subnet prefix                | interface ID   |
+   +------------------------------------------------+----------------+
+
+   Though a very simple router may have no knowledge of the internal
+   structure of IPv6 unicast addresses, routers will more generally have
+   knowledge of one or more of the hierarchical boundaries for the
+   operation of routing protocols.  The known boundaries will differ
+
+
+
+Hinden & Deering            Standards Track                     [Page 7]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   from router to router, depending on what positions the router holds
+   in the routing hierarchy.
+
+
2.5.1 Interface Identifiers

+
+   Interface identifiers in IPv6 unicast addresses are used to identify
+   interfaces on a link.  They are required to be unique within a subnet
+   prefix.  It is recommended that the same interface identifier not be
+   assigned to different nodes on a link.  They may also be unique over
+   a broader scope.  In some cases an interface's identifier will be
+   derived directly from that interface's link-layer address.  The same
+   interface identifier may be used on multiple interfaces on a single
+   node, as long as they are attached to different subnets.
+
+   Note that the uniqueness of interface identifiers is independent of
+   the uniqueness of IPv6 addresses.  For example, a global unicast
+   address may be created with a non-global scope interface identifier
+   and a site-local address may be created with a global scope interface
+   identifier.
+
+   For all unicast addresses, except those that start with binary value
+   000, Interface IDs are required to be 64 bits long and to be
+   constructed in Modified EUI-64 format.
+
+   Modified EUI-64 format based Interface identifiers may have global
+   scope when derived from a global token (e.g., IEEE 802 48-bit MAC or
+   IEEE EUI-64 identifiers [EUI64]) or may have local scope where a
+   global token is not available (e.g., serial links, tunnel end-points,
+   etc.) or where global tokens are undesirable (e.g., temporary tokens
+   for privacy [PRIV]).
+
+   Modified EUI-64 format interface identifiers are formed by inverting
+   the "u" bit (universal/local bit in IEEE EUI-64 terminology) when
+   forming the interface identifier from IEEE EUI-64 identifiers.  In
+   the resulting Modified EUI-64 format the "u" bit is set to one (1) to
+   indicate global scope, and it is set to zero (0) to indicate local
+   scope.  The first three octets in binary of an IEEE EUI-64 identifier
+   are as follows:
+
+       0       0 0       1 1       2
+      |0       7 8       5 6       3|
+      +----+----+----+----+----+----+
+      |cccc|ccug|cccc|cccc|cccc|cccc|
+      +----+----+----+----+----+----+
+
+   written in Internet standard bit-order , where "u" is the
+   universal/local bit, "g" is the individual/group bit, and "c" are the
+   bits of the company_id.  Appendix A: "Creating Modified EUI-64 format
+
+
+
+Hinden & Deering            Standards Track                     [Page 8]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   Interface Identifiers" provides examples on the creation of Modified
+   EUI-64 format based interface identifiers.
+
+   The motivation for inverting the "u" bit when forming an interface
+   identifier is to make it easy for system administrators to hand
+   configure non-global identifiers when hardware tokens are not
+   available.  This is expected to be case for serial links, tunnel end-
+   points, etc.  The alternative would have been for these to be of the
+   form 0200:0:0:1, 0200:0:0:2, etc., instead of the much simpler 1, 2,
+   etc.
+
+   The use of the universal/local bit in the Modified EUI-64 format
+   identifier is to allow development of future technology that can take
+   advantage of interface identifiers with global scope.
+
+   The details of forming interface identifiers are defined in the
+   appropriate "IPv6 over <link>" specification such as "IPv6 over
+   Ethernet" [ETHER], "IPv6 over FDDI" [FDDI], etc.
+
+
2.5.2 The Unspecified Address

+
+   The address 0:0:0:0:0:0:0:0 is called the unspecified address.  It
+   must never be assigned to any node.  It indicates the absence of an
+   address.  One example of its use is in the Source Address field of
+   any IPv6 packets sent by an initializing host before it has learned
+   its own address.
+
+   The unspecified address must not be used as the destination address
+   of IPv6 packets or in IPv6 Routing Headers.  An IPv6 packet with a
+   source address of unspecified must never be forwarded by an IPv6
+   router.
+
+
2.5.3 The Loopback Address

+
+   The unicast address 0:0:0:0:0:0:0:1 is called the loopback address.
+   It may be used by a node to send an IPv6 packet to itself.  It may
+   never be assigned to any physical interface.   It is treated as
+   having link-local scope, and may be thought of as the link-local
+   unicast address of a virtual interface (typically called "the
+   loopback interface") to an imaginary link that goes nowhere.
+
+   The loopback address must not be used as the source address in IPv6
+   packets that are sent outside of a single node.  An IPv6 packet with
+   a destination address of loopback must never be sent outside of a
+   single node and must never be forwarded by an IPv6 router.  A packet
+   received on an interface with destination address of loopback must be
+   dropped.
+
+
+
+
+Hinden & Deering            Standards Track                     [Page 9]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+
2.5.4 Global Unicast Addresses

+
+   The general format for IPv6 global unicast addresses is as follows:
+
+   |         n bits         |   m bits  |       128-n-m bits         |
+   +------------------------+-----------+----------------------------+
+   | global routing prefix  | subnet ID |       interface ID         |
+   +------------------------+-----------+----------------------------+
+
+   where the global routing prefix is a (typically hierarchically-
+   structured) value assigned to a site (a cluster of subnets/links),
+   the subnet ID is an identifier of a link within the site, and the
+   interface ID is as defined in section 2.5.1.
+
+   All global unicast addresses other than those that start with binary
+   000 have a 64-bit interface ID field (i.e., n + m = 64), formatted as
+   described in section 2.5.1.  Global unicast addresses that start with
+   binary 000 have no such constraint on the size or structure of the
+   interface ID field.
+
+   Examples of global unicast addresses that start with binary 000 are
+   the IPv6 address with embedded IPv4 addresses described in section
+   2.5.5 and the IPv6 address containing encoded NSAP addresses
+   specified in [NSAP].  An example of global addresses starting with a
+   binary value other than 000 (and therefore having a 64-bit interface
+   ID field) can be found in [AGGR].
+
+
2.5.5 IPv6 Addresses with Embedded IPv4 Addresses

+
+   The IPv6 transition mechanisms [TRAN] include a technique for hosts
+   and routers to dynamically tunnel IPv6 packets over IPv4 routing
+   infrastructure.  IPv6 nodes that use this technique are assigned
+   special IPv6 unicast addresses that carry a global IPv4 address in
+   the low-order 32 bits.  This type of address is termed an "IPv4-
+   compatible IPv6 address" and has the format:
+
+   |                80 bits               | 16 |      32 bits        |
+   +--------------------------------------+--------------------------+
+   |0000..............................0000|0000|    IPv4 address     |
+   +--------------------------------------+----+---------------------+
+
+   Note: The IPv4 address used in the "IPv4-compatible IPv6 address"
+   must be a globally-unique IPv4 unicast address.
+
+   A second type of IPv6 address which holds an embedded IPv4 address is
+   also defined.  This address type is used to represent the addresses
+   of IPv4 nodes as IPv6 addresses.  This type of address is termed an
+   "IPv4-mapped IPv6 address" and has the format:
+
+
+
+Hinden & Deering            Standards Track                    [Page 10]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   |                80 bits               | 16 |      32 bits        |
+   +--------------------------------------+--------------------------+
+   |0000..............................0000|FFFF|    IPv4 address     |
+   +--------------------------------------+----+---------------------+
+
+
2.5.6 Local-Use IPv6 Unicast Addresses

+
+   There are two types of local-use unicast addresses defined.  These
+   are Link-Local and Site-Local.  The Link-Local is for use on a single
+   link and the Site-Local is for use in a single site.  Link-Local
+   addresses have the following format:
+
+   |   10     |
+   |  bits    |         54 bits         |          64 bits           |
+   +----------+-------------------------+----------------------------+
+   |1111111010|           0             |       interface ID         |
+   +----------+-------------------------+----------------------------+
+
+   Link-Local addresses are designed to be used for addressing on a
+   single link for purposes such as automatic address configuration,
+   neighbor discovery, or when no routers are present.
+
+   Routers must not forward any packets with link-local source or
+   destination addresses to other links.
+
+   Site-Local addresses have the following format:
+
+   |   10     |
+   |  bits    |         54 bits         |         64 bits            |
+   +----------+-------------------------+----------------------------+
+   |1111111011|        subnet ID        |       interface ID         |
+   +----------+-------------------------+----------------------------+
+
+   Site-local addresses are designed to be used for addressing inside of
+   a site without the need for a global prefix.  Although a subnet ID
+   may be up to 54-bits long, it is expected that globally-connected
+   sites will use the same subnet IDs for site-local and global
+   prefixes.
+
+   Routers must not forward any packets with site-local source or
+   destination addresses outside of the site.
+
+
+
+
+
+
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 11]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+
2.6 Anycast Addresses

+
+   An IPv6 anycast address is an address that is assigned to more than
+   one interface (typically belonging to different nodes), with the
+   property that a packet sent to an anycast address is routed to the
+   "nearest" interface having that address, according to the routing
+   protocols' measure of distance.
+
+   Anycast addresses are allocated from the unicast address space, using
+   any of the defined unicast address formats.  Thus, anycast addresses
+   are syntactically indistinguishable from unicast addresses.  When a
+   unicast address is assigned to more than one interface, thus turning
+   it into an anycast address, the nodes to which the address is
+   assigned must be explicitly configured to know that it is an anycast
+   address.
+
+   For any assigned anycast address, there is a longest prefix P of that
+   address that identifies the topological region in which all
+   interfaces belonging to that anycast address reside.  Within the
+   region identified by P, the anycast address must be maintained as a
+   separate entry in the routing system (commonly referred to as a "host
+   route"); outside the region identified by P, the anycast address may
+   be aggregated into the routing entry for prefix P.
+
+   Note that in the worst case, the prefix P of an anycast set may be
+   the null prefix, i.e., the members of the set may have no topological
+   locality.  In that case, the anycast address must be maintained as a
+   separate routing entry throughout the entire internet, which presents
+   a severe scaling limit on how many such "global" anycast sets may be
+   supported.  Therefore, it is expected that support for global anycast
+   sets may be unavailable or very restricted.
+
+   One expected use of anycast addresses is to identify the set of
+   routers belonging to an organization providing internet service.
+   Such addresses could be used as intermediate addresses in an IPv6
+   Routing header, to cause a packet to be delivered via a particular
+   service provider or sequence of service providers.
+
+   Some other possible uses are to identify the set of routers attached
+   to a particular subnet, or the set of routers providing entry into a
+   particular routing domain.
+
+   There is little experience with widespread, arbitrary use of internet
+   anycast addresses, and some known complications and hazards when
+   using them in their full generality [ANYCST].  Until more experience
+   has been gained and solutions are specified, the following
+   restrictions are imposed on IPv6 anycast addresses:
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 12]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   o  An anycast address must not be used as the source address of an
+      IPv6 packet.
+
+   o  An anycast address must not be assigned to an IPv6 host, that is,
+      it may be assigned to an IPv6 router only.
+
+
2.6.1 Required Anycast Address

+
+   The Subnet-Router anycast address is predefined.  Its format is as
+   follows:
+
+   |                         n bits                 |   128-n bits   |
+   +------------------------------------------------+----------------+
+   |                   subnet prefix                | 00000000000000 |
+   +------------------------------------------------+----------------+
+
+   The "subnet prefix" in an anycast address is the prefix which
+   identifies a specific link.  This anycast address is syntactically
+   the same as a unicast address for an interface on the link with the
+   interface identifier set to zero.
+
+   Packets sent to the Subnet-Router anycast address will be delivered
+   to one router on the subnet.  All routers are required to support the
+   Subnet-Router anycast addresses for the subnets to which they have
+   interfaces.
+
+   The subnet-router anycast address is intended to be used for
+   applications where a node needs to communicate with any one of the
+   set of routers.
+
+
2.7 Multicast Addresses

+
+   An IPv6 multicast address is an identifier for a group of interfaces
+   (typically on different nodes).  An interface may belong to any
+   number of multicast groups.  Multicast addresses have the following
+   format:
+
+   |   8    |  4 |  4 |                  112 bits                   |
+   +------ -+----+----+---------------------------------------------+
+   |11111111|flgs|scop|                  group ID                   |
+   +--------+----+----+---------------------------------------------+
+
+         binary 11111111 at the start of the address identifies the
+         address as being a multicast address.
+
+                                       +-+-+-+-+
+         flgs is a set of 4 flags:     |0|0|0|T|
+                                       +-+-+-+-+
+
+
+
+Hinden & Deering            Standards Track                    [Page 13]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+            The high-order 3 flags are reserved, and must be initialized
+            to 0.
+
+            T = 0 indicates a permanently-assigned ("well-known")
+            multicast address, assigned by the Internet Assigned Number
+            Authority (IANA).
+
+            T = 1 indicates a non-permanently-assigned ("transient")
+            multicast address.
+
+         scop is a 4-bit multicast scope value used to limit the scope
+         of the multicast group.  The values are:
+
+            0  reserved
+            1  interface-local scope
+            2  link-local scope
+            3  reserved
+            4  admin-local scope
+            5  site-local scope
+            6  (unassigned)
+            7  (unassigned)
+            8  organization-local scope
+            9  (unassigned)
+            A  (unassigned)
+            B  (unassigned)
+            C  (unassigned)
+            D  (unassigned)
+            E  global scope
+            F  reserved
+
+            interface-local scope spans only a single interface on a
+            node, and is useful only for loopback transmission of
+            multicast.
+
+            link-local and site-local multicast scopes span the same
+            topological regions as the corresponding unicast scopes.
+
+            admin-local scope is the smallest scope that must be
+            administratively configured, i.e., not automatically derived
+            from physical connectivity or other, non- multicast-related
+            configuration.
+
+            organization-local scope is intended to span multiple sites
+            belonging to a single organization.
+
+            scopes labeled "(unassigned)" are available for
+            administrators to define additional multicast regions.
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 14]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+         group ID identifies the multicast group, either permanent or
+         transient, within the given scope.
+
+   The "meaning" of a permanently-assigned multicast address is
+   independent of the scope value.  For example, if the "NTP servers
+   group" is assigned a permanent multicast address with a group ID of
+   101 (hex), then:
+
+      FF01:0:0:0:0:0:0:101 means all NTP servers on the same interface
+      (i.e., the same node) as the sender.
+
+      FF02:0:0:0:0:0:0:101 means all NTP servers on the same link as the
+      sender.
+
+      FF05:0:0:0:0:0:0:101 means all NTP servers in the same site as the
+      sender.
+
+      FF0E:0:0:0:0:0:0:101 means all NTP servers in the internet.
+
+   Non-permanently-assigned multicast addresses are meaningful only
+   within a given scope.  For example, a group identified by the non-
+   permanent, site-local multicast address FF15:0:0:0:0:0:0:101 at one
+   site bears no relationship to a group using the same address at a
+   different site, nor to a non-permanent group using the same group ID
+   with different scope, nor to a permanent group with the same group
+   ID.
+
+   Multicast addresses must not be used as source addresses in IPv6
+   packets or appear in any Routing header.
+
+   Routers must not forward any multicast packets beyond of the scope
+   indicated by the scop field in the destination multicast address.
+
+   Nodes must not originate a packet to a multicast address whose scop
+   field contains the reserved value 0; if such a packet is received, it
+   must be silently dropped.  Nodes should not originate a packet to a
+   multicast address whose scop field contains the reserved value F; if
+   such a packet is sent or received, it must be treated the same as
+   packets destined to a global (scop E) multicast address.
+
+
2.7.1 Pre-Defined Multicast Addresses

+
+   The following well-known multicast addresses are pre-defined.  The
+   group ID's defined in this section are defined for explicit scope
+   values.
+
+   Use of these group IDs for any other scope values, with the T flag
+   equal to 0, is not allowed.
+
+
+
+Hinden & Deering            Standards Track                    [Page 15]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+      Reserved Multicast Addresses:   FF00:0:0:0:0:0:0:0
+                                      FF01:0:0:0:0:0:0:0
+                                      FF02:0:0:0:0:0:0:0
+                                      FF03:0:0:0:0:0:0:0
+                                      FF04:0:0:0:0:0:0:0
+                                      FF05:0:0:0:0:0:0:0
+                                      FF06:0:0:0:0:0:0:0
+                                      FF07:0:0:0:0:0:0:0
+                                      FF08:0:0:0:0:0:0:0
+                                      FF09:0:0:0:0:0:0:0
+                                      FF0A:0:0:0:0:0:0:0
+                                      FF0B:0:0:0:0:0:0:0
+                                      FF0C:0:0:0:0:0:0:0
+                                      FF0D:0:0:0:0:0:0:0
+                                      FF0E:0:0:0:0:0:0:0
+                                      FF0F:0:0:0:0:0:0:0
+
+   The above multicast addresses are reserved and shall never be
+   assigned to any multicast group.
+
+      All Nodes Addresses:    FF01:0:0:0:0:0:0:1
+                              FF02:0:0:0:0:0:0:1
+
+   The above multicast addresses identify the group of all IPv6 nodes,
+   within scope 1 (interface-local) or 2 (link-local).
+
+      All Routers Addresses:   FF01:0:0:0:0:0:0:2
+                               FF02:0:0:0:0:0:0:2
+                               FF05:0:0:0:0:0:0:2
+
+   The above multicast addresses identify the group of all IPv6 routers,
+   within scope 1 (interface-local), 2 (link-local), or 5 (site-local).
+
+      Solicited-Node Address:  FF02:0:0:0:0:1:FFXX:XXXX
+
+   Solicited-node multicast address are computed as a function of a
+   node's unicast and anycast addresses.  A solicited-node multicast
+   address is formed by taking the low-order 24 bits of an address
+   (unicast or anycast) and appending those bits to the prefix
+   FF02:0:0:0:0:1:FF00::/104 resulting in a multicast address in the
+   range
+
+      FF02:0:0:0:0:1:FF00:0000
+
+   to
+
+      FF02:0:0:0:0:1:FFFF:FFFF
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 16]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   For example, the solicited node multicast address corresponding to
+   the IPv6 address 4037::01:800:200E:8C6C is FF02::1:FF0E:8C6C.  IPv6
+   addresses that differ only in the high-order bits, e.g., due to
+   multiple high-order prefixes associated with different aggregations,
+   will map to the same solicited-node address thereby, reducing the
+   number of multicast addresses a node must join.
+
+   A node is required to compute and join (on the appropriate interface)
+   the associated Solicited-Node multicast addresses for every unicast
+   and anycast address it is assigned.
+
+
2.8 A Node's Required Addresses

+
+   A host is required to recognize the following addresses as
+   identifying itself:
+
+      o  Its required Link-Local Address for each interface.
+      o  Any additional Unicast and Anycast Addresses that have been
+         configured for the node's interfaces (manually or
+         automatically).
+      o  The loopback address.
+      o  The All-Nodes Multicast Addresses defined in section 2.7.1.
+      o  The Solicited-Node Multicast Address for each of its unicast
+         and anycast addresses.
+      o  Multicast Addresses of all other groups to which the node
+         belongs.
+
+   A router is required to recognize all addresses that a host is
+   required to recognize, plus the following addresses as identifying
+   itself:
+
+      o  The Subnet-Router Anycast Addresses for all interfaces for
+         which it is configured to act as a router.
+      o  All other Anycast Addresses with which the router has been
+         configured.
+      o  The All-Routers Multicast Addresses defined in section 2.7.1.
+
+
3. Security Considerations

+
+   IPv6 addressing documents do not have any direct impact on Internet
+   infrastructure security.  Authentication of IPv6 packets is defined
+   in [AUTH].
+
+
+
+
+
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 17]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+
4. IANA Considerations

+
+   The table and notes at http://www.isi.edu/in-
+   notes/iana/assignments/ipv6-address-space.txt should be replaced with
+   the following:
+
+   INTERNET PROTOCOL VERSION 6 ADDRESS SPACE
+
+   The initial assignment of IPv6 address space is as follows:
+
+   Allocation                            Prefix         Fraction of
+                                         (binary)       Address Space
+   -----------------------------------   --------       -------------
+   Unassigned (see Note 1 below)         0000 0000      1/256
+   Unassigned                            0000 0001      1/256
+   Reserved for NSAP Allocation          0000 001       1/128 [RFC1888]
+   Unassigned                            0000 01        1/64
+   Unassigned                            0000 1         1/32
+   Unassigned                            0001           1/16
+   Global Unicast                        001            1/8   [RFC2374]
+   Unassigned                            010            1/8
+   Unassigned                            011            1/8
+   Unassigned                            100            1/8
+   Unassigned                            101            1/8
+   Unassigned                            110            1/8
+   Unassigned                            1110           1/16
+   Unassigned                            1111 0         1/32
+   Unassigned                            1111 10        1/64
+   Unassigned                            1111 110       1/128
+   Unassigned                            1111 1110 0    1/512
+   Link-Local Unicast Addresses          1111 1110 10   1/1024
+   Site-Local Unicast Addresses          1111 1110 11   1/1024
+   Multicast Addresses                   1111 1111      1/256
+
+   Notes:
+
+   1. The "unspecified address", the "loopback address", and the IPv6
+      Addresses with Embedded IPv4 Addresses are assigned out of the
+      0000 0000 binary prefix space.
+
+   2. For now, IANA should limit its allocation of IPv6 unicast address
+      space to the range of addresses that start with binary value 001.
+      The rest of the global unicast address space (approximately 85% of
+      the IPv6 address space) is reserved for future definition and use,
+      and is not to be assigned by IANA at this time.
+
+
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 18]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+
5.  References

+
+
5.1  Normative References

+
+   [IPV6]    Deering, S. and R. Hinden, "Internet Protocol, Version 6
+             (IPv6) Specification", RFC 2460, December 1998.
+
+   [RFC2026] Bradner, S., "The Internet Standards Process -- Revision
+             3", BCP 9 , RFC 2026, October 1996.
+
+
5.2  Informative References

+
+   [ANYCST]  Partridge, C., Mendez, T. and W. Milliken, "Host Anycasting
+             Service", RFC 1546, November 1993.
+
+   [AUTH]    Kent, S. and R. Atkinson, "IP Authentication Header", RFC
+             2402, November 1998.
+
+   [AGGR]    Hinden, R., O'Dell, M. and S. Deering, "An Aggregatable
+             Global Unicast Address Format", RFC 2374, July 1998.
+
+   [CIDR]    Fuller, V., Li, T., Yu, J. and K. Varadhan, "Classless
+             Inter-Domain Routing (CIDR): An Address Assignment and
+             Aggregation Strategy", RFC 1519, September 1993.
+
+   [ETHER]   Crawford, M., "Transmission of IPv6 Packets over Ethernet
+             Networks", RFC 2464, December 1998.
+
+   [EUI64]   IEEE, "Guidelines for 64-bit Global Identifier (EUI-64)
+             Registration Authority",
+             http://standards.ieee.org/regauth/oui/tutorials/EUI64.html,
+             March 1997.
+
+   [FDDI]    Crawford, M., "Transmission of IPv6 Packets over FDDI
+             Networks", RFC 2467, December 1998.
+
+   [MASGN]   Hinden, R. and S. Deering, "IPv6 Multicast Address
+             Assignments", RFC 2375, July 1998.
+
+   [NSAP]    Bound, J., Carpenter, B., Harrington, D., Houldsworth, J.
+             and A. Lloyd, "OSI NSAPs and IPv6", RFC 1888, August 1996.
+
+   [PRIV]    Narten, T. and R. Draves, "Privacy Extensions for Stateless
+             Address Autoconfiguration in IPv6", RFC 3041, January 2001.
+
+   [TOKEN]   Crawford, M., Narten, T. and S. Thomas, "Transmission of
+             IPv6 Packets over Token Ring Networks", RFC 2470, December
+             1998.
+
+
+
+Hinden & Deering            Standards Track                    [Page 19]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   [TRAN]    Gilligan, R. and E. Nordmark, "Transition Mechanisms for
+             IPv6 Hosts and Routers", RFC 2893, August 2000.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 20]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+APPENDIX A: Creating Modified EUI-64 format Interface Identifiers
+
+   Depending on the characteristics of a specific link or node there are
+   a number of approaches for creating Modified EUI-64 format interface
+   identifiers.  This appendix describes some of these approaches.
+
+Links or Nodes with IEEE EUI-64 Identifiers
+
+   The only change needed to transform an IEEE EUI-64 identifier to an
+   interface identifier is to invert the "u" (universal/local) bit.  For
+   example, a globally unique IEEE EUI-64 identifier of the form:
+
+   |0              1|1              3|3              4|4              6|
+   |0              5|6              1|2              7|8              3|
+   +----------------+----------------+----------------+----------------+
+   |cccccc0gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm|mmmmmmmmmmmmmmmm|
+   +----------------+----------------+----------------+----------------+
+
+   where "c" are the bits of the assigned company_id, "0" is the value
+   of the universal/local bit to indicate global scope, "g" is
+   individual/group bit, and "m" are the bits of the manufacturer-
+   selected extension identifier.  The IPv6 interface identifier would
+   be of the form:
+
+   |0              1|1              3|3              4|4              6|
+   |0              5|6              1|2              7|8              3|
+   +----------------+----------------+----------------+----------------+
+   |cccccc1gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm|mmmmmmmmmmmmmmmm|
+   +----------------+----------------+----------------+----------------+
+
+   The only change is inverting the value of the universal/local bit.
+
+Links or Nodes with IEEE 802 48 bit MAC's
+
+   [EUI64] defines a method to create a IEEE EUI-64 identifier from an
+   IEEE 48bit MAC identifier.  This is to insert two octets, with
+   hexadecimal values of 0xFF and 0xFE, in the middle of the 48 bit MAC
+   (between the company_id and vendor supplied id).  For example, the 48
+   bit IEEE MAC with global scope:
+
+
+
+
+
+
+
+
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 21]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   |0              1|1              3|3              4|
+   |0              5|6              1|2              7|
+   +----------------+----------------+----------------+
+   |cccccc0gcccccccc|ccccccccmmmmmmmm|mmmmmmmmmmmmmmmm|
+   +----------------+----------------+----------------+
+
+   where "c" are the bits of the assigned company_id, "0" is the value
+   of the universal/local bit to indicate global scope, "g" is
+   individual/group bit, and "m" are the bits of the manufacturer-
+   selected extension identifier.  The interface identifier would be of
+   the form:
+
+   |0              1|1              3|3              4|4              6|
+   |0              5|6              1|2              7|8              3|
+   +----------------+----------------+----------------+----------------+
+   |cccccc1gcccccccc|cccccccc11111111|11111110mmmmmmmm|mmmmmmmmmmmmmmmm|
+   +----------------+----------------+----------------+----------------+
+
+   When IEEE 802 48bit MAC addresses are available (on an interface or a
+   node), an implementation may use them to create interface identifiers
+   due to their availability and uniqueness properties.
+
+Links with Other Kinds of Identifiers
+
+   There are a number of types of links that have link-layer interface
+   identifiers other than IEEE EIU-64 or IEEE 802 48-bit MACs.  Examples
+   include LocalTalk and Arcnet.  The method to create an Modified EUI-
+   64 format identifier is to take the link identifier (e.g., the
+   LocalTalk 8 bit node identifier) and zero fill it to the left.  For
+   example, a LocalTalk 8 bit node identifier of hexadecimal value 0x4F
+   results in the following interface identifier:
+
+   |0              1|1              3|3              4|4              6|
+   |0              5|6              1|2              7|8              3|
+   +----------------+----------------+----------------+----------------+
+   |0000000000000000|0000000000000000|0000000000000000|0000000001001111|
+   +----------------+----------------+----------------+----------------+
+
+   Note that this results in the universal/local bit set to "0" to
+   indicate local scope.
+
+Links without Identifiers
+
+   There are a number of links that do not have any type of built-in
+   identifier.  The most common of these are serial links and configured
+   tunnels.  Interface identifiers must be chosen that are unique within
+   a subnet-prefix.
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 22]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   When no built-in identifier is available on a link the preferred
+   approach is to use a global interface identifier from another
+   interface or one which is assigned to the node itself.  When using
+   this approach no other interface connecting the same node to the same
+   subnet-prefix may use the same identifier.
+
+   If there is no global interface identifier available for use on the
+   link the implementation needs to create a local-scope interface
+   identifier.  The only requirement is that it be unique within a
+   subnet prefix.  There are many possible approaches to select a
+   subnet-prefix-unique interface identifier.  These include:
+
+      Manual Configuration
+      Node Serial Number
+      Other node-specific token
+
+   The subnet-prefix-unique interface identifier should be generated in
+   a manner that it does not change after a reboot of a node or if
+   interfaces are added or deleted from the node.
+
+   The selection of the appropriate algorithm is link and implementation
+   dependent.  The details on forming interface identifiers are defined
+   in the appropriate "IPv6 over <link>" specification.  It is strongly
+   recommended that a collision detection algorithm be implemented as
+   part of any automatic algorithm.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Hinden & Deering            Standards Track                    [Page 23]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+APPENDIX B: Changes from RFC-2373
+
+   The following changes were made from RFC-2373 "IP Version 6
+   Addressing Architecture":
+
+   -  Clarified text in section 2.2 to allow "::" to represent one or
+      more groups of 16 bits of zeros.
+   -  Changed uniqueness requirement of Interface Identifiers from
+      unique on a link to unique within a subnet prefix.  Also added a
+      recommendation that the same interface identifier not be assigned
+      to different machines on a link.
+   -  Change site-local format to make the subnet ID field 54-bit long
+      and remove the 38-bit zero's field.
+   -  Added description of multicast scop values and rules to handle the
+      reserved scop value 0.
+   -  Revised sections 2.4 and 2.5.6 to simplify and clarify how
+      different address types  are identified.  This was done to insure
+      that implementations do not build in any knowledge about global
+      unicast format prefixes.  Changes include:
+         o  Removed Format Prefix (FP) terminology
+         o  Revised list of address types to only include exceptions to
+            global unicast and a singe entry that identifies everything
+            else as Global Unicast.
+         o  Removed list of defined prefix exceptions from section 2.5.6
+            as it is now the main part of section 2.4.
+   -  Clarified text relating to EUI-64 identifiers to distinguish
+      between IPv6's "Modified EUI-64 format" identifiers and IEEE EUI-
+      64 identifiers.
+   -  Combined the sections on the Global Unicast Addresses and NSAP
+      Addresses into a single section on Global Unicast Addresses,
+      generalized the Global Unicast format, and cited [AGGR] and [NSAP]
+      as examples.
+   -  Reordered sections 2.5.4 and 2.5.5.
+   -  Removed section 2.7.2 Assignment of New IPv6 Multicast Addresses
+      because this is being redefined elsewhere.
+   -  Added an IANA considerations section that updates the IANA IPv6
+      address allocations and documents the NSAP and AGGR allocations.
+   -  Added clarification that the "IPv4-compatible IPv6 address" must
+      use global IPv4 unicast addresses.
+   -  Divided references in to normative and non-normative sections.
+   -  Added reference to [PRIV] in section 2.5.1
+   -  Added clarification that routers must not forward multicast
+      packets outside of the scope indicated in the multicast address.
+   -  Added clarification that routers must not forward packets with
+       source address of the unspecified address.
+   -  Added clarification that routers must drop packets received on an
+      interface with destination address of loopback.
+   -  Clarified the definition of IPv4-mapped addresses.
+
+
+
+Hinden & Deering            Standards Track                    [Page 24]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+   -  Removed the ABNF Description of Text Representations Appendix.
+   -  Removed the address block reserved for IPX addresses.
+   -  Multicast scope changes:
+         o  Changed name of scope value 1 from "node-local" to
+            "interface-local"
+         o  Defined scope value 4 as "admin-local"
+   -  Corrected reference to RFC1933 and updated references.
+   -  Many small changes to clarify and make the text more consistent.
+
+Authors' Addresses
+
+   Robert M. Hinden
+   Nokia
+   313 Fairchild Drive
+   Mountain View, CA 94043
+   USA
+
+   Phone: +1 650 625-2004
+   EMail: hinden@iprg.nokia.com
+
+
+   Stephen E. Deering
+   Cisco Systems, Inc.
+   170 West Tasman Drive
+   San Jose, CA 95134-1706
+   USA
+
+   Phone: +1 408 527-8213
+   EMail: deering@cisco.com
+
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+Hinden & Deering            Standards Track                    [Page 25]
+ 
+RFC 3513              IPv6 Addressing Architecture            April 2003
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2003).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assigns.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
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+Hinden & Deering            Standards Track                    [Page 26]
+ 
+
+

+Html markup produced by rfcmarkup 1.46, available from +http://tools.ietf.org/tools/rfcmarkup/ + + + \ No newline at end of file -- cgit v1.2.3