rfc1069.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.


RFC 1069                   IP ISO Addressing               February 1989


   The Authority and Format Identifier (AFI) is "47" (BCD).  The Initial
   Domain Identifier (IDI) consists of the International Code Designator
   (ICD) assigned to the Internet, and must contain the value "0006".
   The Version Number must contain the value "02".  The Global Area
   Number must contains the value "00".  The Padding field is of
   variable length, but must contain the value zero.

4.  Specific Values for use with the IGP specific field

   In general, a particular routing domain may specify any addressing
   scheme for use with the IGP specific part of the address, up to 11
   octets in length (consistent with the maximum address length of 20
   octets).  However, it is expected that initially addresses used in
   this field will consist of either the current IP addresses, or
   addresses conformant with those specified in the draft ANSI proposal
   for intra-domain routing.

   For end systems which are members of routing domains using the IP
   addresses for internal routing, the addresses will look as follows:
































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RFC 1069                   IP ISO Addressing               February 1989


                                                  Octet

                       +------------------------+
                       |          AFI           |     1
                       +------------------------+
                       |       IDI / ICD        |     2
                       +--                    --+
                       |(specifies DoD Internet)|     3
                       +------------------------+
                       |     Version Number     |     4
                       +------------------------+
                       |      Global Area       |     5
                       +---                  ---+
                       |         Number         |     6
                       +------------------------+
                       |        Routing         |     7
                       +---                  ---+
                       |         Domain         |     8
                       +------------------------+
                       |                        |     9
                       :        Padding         :     :
                       :                        :     :
                       |                        |    15
                       +------------------------+
                       |       Four Octet       |    16
                       +---                  ---+
                       |        Internet        |    17
                       +---                  ---+
                       |          DoD           |    18
                       +---                  ---+
                       |        Address         |    19
                       +------------------------+
                       |        Selector        |    20
                       +------------------------+

           Figure 3: ISO IP Address with Encoded DoD IP Address

   For end systems which are members of routing domains using the
   address format specified in the draft ANSI proposal for intra-domain
   routing [6], the addresses will look as follows:











Callon & Braun                                                  [Page 7]

RFC 1069                   IP ISO Addressing               February 1989


                                                  Octet

                       +------------------------+
                       |          AFI           |     1
                       +------------------------+
                       |       IDI / ICD        |     2
                       +--                    --+
                       |(specifies DOD Internet)|     3
                       +------------------------+
                       |     Version Number     |     4
                       +------------------------+
                       |      Global Area       |     5
                       +---                  ---+
                       |         Number         |     6
                       +------------------------+
                       |        Routing         |     7
                       +---                  ---+
                       |         Domain         |     8
                       +------------------------+
                       |                        |     9
                       +---                  ---+
                       |        Padding         |    10
                       +---                  ---+
                       |                        |    11
                       +------------------------+
                       |                        |    12
                       +---     LOC-AREA     ---+
                       |                        |    13
                       +------------------------+
                       |                        |    14
                       :           ID           :     :
                       :                        :     :
                       |                        |    19
                       +------------------------+
                       |        Selector        |    20
                       +------------------------+

         Figure 4: ISO IP Address with Encoded ANSI-format Address

5.  Devices Attached to PDNs

   Otherwise isolated end systems, which are attached to the Internet
   only indirectly via public data networks, and simple LANs which are
   similarly attached only via Public Data Networks, may make use of a
   separate address format based on their X.121 address.  Such addresses
   may, for example, use the ISO-X.121 address format discussed in [3].
   These addresses will need to be handled for routing purposes in much
   the same way as addresses in routing domains which have been



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RFC 1069                   IP ISO Addressing               February 1989


   interconnected to the Internet, but which use other address formats,
   such as those specified by national standards bodies.

6.  Migration to Future Routing Protocols

   Initially, routing of ISO datagrams in the Internet may make use of
   the first 8 octets of the address (AFI, ICD, version, global area
   number, and routing domain number) as a flat field identifying the
   routing domain.  This implies that if EGP is initially used for
   routing between routing domains, a new version of EGP may be required
   to carry 8 octet routing domain numbers instead of 3 octet network
   numbers.

   There are currently several efforts underway to determine the
   requirements for inter-autonomous system routing, and to define a new
   protocol.  One of the requirements of inter-autonomous system routing
   is the need to be able to deal with a very large Internet.  It is
   anticipated that during the lifetime of the addressing scheme
   described in this RFC the number of networks in the Internet will
   grow to the point where it is no longer feasible for any gateway to
   maintain separate routes to every network in the Internet.  Allowing
   inter-domain routing to be done by routing domain number instead of
   network number is therefore a necessary step in the long term.

   It is difficult to anticipate the rate at which the number of routing
   domains may grow.  For example, during a period of time in which the
   number of networks grows by a factor of 100, it is not clear whether
   the number of routing domains may also be expected to grow by a
   factor of 100, or by some lesser amount.  It is possible that the
   number of routing domains will also grow to a point where it is not
   feasible for a single gateway to maintain separate routes to each.
   In order to prepare for this eventuality, we have provided for a
   "global area" field.

   In the long term, it will be necessary for gateways to route to
   destinations which are in routing domains utilizing other addressing
   formats, specified by other organizations such as ANSI, ECMA, etc.
   In this case, it will not be possible to ensure that the first 8
   octets of the address specifies the routing domain.  In the long
   term, it will therefore be necessary to route based on variable
   length routing domain identifiers.  It may be assumed that future
   inter-domain routing protocols will allow for specification of either
   (1) an address mask, specifying which part of an address is relevant
   for specifying those destinations which are reachable via a
   particular domain; or (2) a length field, specifying how many leading
   octets in a particular address are relevant.  Specification of the
   details of such a routing protocol is beyond the scope of this
   document.



Callon & Braun                                                  [Page 9]

RFC 1069                   IP ISO Addressing               February 1989


References

   [1]  ISO, "Protocol for Providing the Connectionless-Mode Network
        Services", RFC-926, ISO, December 1984.

   [2]  ANSI, "Guidelines for the Specification of the Structure of the
        Domain Specific Part (DSP) of the ISO Standard NSAP Address",
        RFC-982, ANSI Working Document X3S3.3/85-258, April 1986.

   [3]  ISO, Draft International Standard 8348/DAD2, "Information
        Processing Systems  --  Data Communications  --  Network Service
        Definition, Addendum 2 Covering Network Layer Addressing", RFC-
        941, April 1985.

   [4]  Reynolds, J. and J. Postel, "Assigned Numbers", RFC-1010,
        USC/Information Sciences Institute, May 1987.

   [5]  Callon, R. and H. W. Braun, "Working Draft -- Guidelines for the
        use of Internet-IP addresses in the ISO Connectionless-Mode
        Network Protocol," RFC-986, June 1986.

   [6]  ISO TC97/SC6/WG2 working document, "Intermediate System to
        Intermediate System Intra-Domain Routing Exchange Protocol".




























Callon & Braun                                                 [Page 10]