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diff --git a/contrib/bind9/doc/rfc/rfc3513.txt b/contrib/bind9/doc/rfc/rfc3513.txt deleted file mode 100644 index 49c0fa4..0000000 --- a/contrib/bind9/doc/rfc/rfc3513.txt +++ /dev/null @@ -1,1459 +0,0 @@ - - - - - - -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. - - - - - - - - - - - - - - - - - - - - - - - -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 - - - - - - - - - - - - - - - - - - - - - - -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 - - - - - - - - - - - - - - - - - - - - - - -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. - - - - - - - - - - - - - - - - - - - -Hinden & Deering Standards Track [Page 26] - |
