RFC 1887 (rfc1887) - Page 3 of 26

An Architecture for IPv6 Unicast Address Allocation

RFC 1887      IPv6 Unicast Address Allocation Architecture December 1995


        architecture for such embedded addresses;

      - Multicast addressing;

      - Address allocation for mobile hosts;

      - Identification of specific administrative domains in the
        Internet;

      - Policy or mechanisms for making registered information known to
        third parties (such as the entity to which a specific IPv6
        address or a potion of the IPv6 address space has been
        allocated);

      - How a routing domain (especially a site) should organize its
        internal topology or allocate portions of its IPv6 address
        space; the relationship between topology and addresses is
        discussed, but the method of deciding on a particular topology
        or internal addressing plan is not; and,

      - Procedures for assigning host IPv6 addresses.


2.   Background


   Some background information is provided in this section that is
   helpful in understanding the issues involved in IPv6 address
   allocation. A brief discussion of IPv6 routing is provided.

   IPv6 partitions the routing problem into three parts:

      - Routing exchanges between end systems and routers,

      - Routing exchanges between routers in the same routing domain,
        and,

      - Routing among routing domains.


3.   IPv6 Addresses and Routing


   For the purposes of this paper, an IPv6 address prefix is defined as
   an IPv6 address and some indication of the leftmost contiguous
   significant bits within this address portion.  Throughout this paper
   IPv6 address prefixes will be represented as X/Y, where X is a prefix
   of an IPv6 address in length greater than or equal to that specified



Rekhter & Li                 Informational