a crude method of limiting long-prefix propagation

[Yakov Rekhter]

Ben,

> Yakov,
> 	Can you provide a reference for this?  I am rather far along in
> my definition of the PROP_PATH and its behavior, but any input like this
> is welcome.

see below... 

Yakov.
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   7.12.5  DIST_LIST_INCL

      DIST_LIST_INCL is an optional transitive attribute.  It
      shall be recognized upon receipt by all routers.  When present,
      this attribute lists the ASs of the routing domains to which
      the routing information may be distributed.

      When a router receives an UPDATE message that contains the
      DIST_LIST_INCL attribute, then the receiving router shall
      not redistribute the associated routing information to any
      router which is not a member of at least one autonomous system
      whose AS is contained in this attribute.

      A router shall redistribute only that information which has
      been locally selected as a route, and shall redistribute it
      only to autonomous systems which are both adjacent to it and
      are included in the distribution list.  A router may distribute
      the information to any adjacent router that is a member of
      any routing domain or confederation whose AS is contained in
      DIST_LIST_INCL.  A router is not required to distribute the
      routing information to every autonomous system whose AS is
      listed.

      If a router receives an UPDATE message that doesn't contain
      the DIST_LIST_INCL attribute, then it may distribute the
      routing information to all adjacent routers.  Alternatively,
      the local router may also add a DIST_LIST_INCL attribute, to
      the route information.  If the DIST_LIST_INCL attribute is
      present and has a length of zero octets, then the routing
      information may be used locally, but shall not be advertised
      to any other router.

      When it originates an UPDATE message which describes a route
      to destinations located in its own routing domain, a router
      may append the DIST_LIST_INCL attribute, in accordance with
      its local policies.

      If a router chooses to advertise a route which was learned
      from an UPDATE message which already contained the DIST_LIST_INCL
      attribute, the advertising router may modify this attribute
      by pruning the set of ASs included in the list.  If a router
      chooses to prune the set, it shall not delete the AS of its
      own autonomous system.  However, if the reduced list is empty
      (that is, has a length of zero), then the router shall not
      advertise the routing information to any router located in
      a different routing domain.