    Network Working Group                                 C. Huitema, Chair
    Request for Comments: 1481                  Internet Architecture Board
                                                                  July 1993

               IAB Recommendation for an Intermediate Strategy to
                         Address the Issue of Scaling

    Status of this Memo

       This memo provides information for the Internet community.  It does
       not specify an Internet standard.  Distribution of this memo is
       unlimited.

    Recommendation

       Classless Inter-Domain Routing (CIDR) proposes strategies for address
       assignment of the existing IP address space with a view to conserve
       the address space and stem the explosive growth of routing tables in
       default-route-free routers run by transit routing domain providers
       [1].  CIDR is proposed as an immediate term strategy to extend the
       life of the current 32 bit IP address space.  This strategy presumes
       that a suitable long term solution is being addressed within the
       Internet technical community.

       The basic components of the CIDR plan are: management of the
       allocation of Internet address space and provision of a mechanism for
       aggregation of routing information.  The IP community has published
       several RFCs and Internet-Drafts which describe the architecture for
       IP address assignment and routing protocols which will promote the
       deployment of CIDR.  These documents have led to changes in the way
       network address are allocated and have prompted enhancements to the
       inter-domain and intra-domain routing protocols.

       With the CIDR prompted changes in the management of the allocation of
       the Internet address space, allocation of blocks of Class C numbers
       leads to an explosion of the routing tables.  So, it is important
       that the techniques for aggregating information in the routing
       protocols keep pace with the change in the allocation of IP numbers.

       The IAB endorses the CIDR architecture and its implementation.  In
       addition, the IAB supports the actions taken by the IANA and
       InterNIC, the router vendors, and the network operators to implement
       CIDR to address the scaling problem that we are facing with the
       growth of the Internet.

    IAB                                                             [Page 1]

    RFC 1481                      IAB on CIDR                      July 1993

    References

       [1] Fuller, V., Li, T., Yu, J., and K. Varadhan, "Supernetting: an
           Address Assignment and Aggregation Strategy", RFC 1338, BARRNet,
           cisco, Merit, OARnet, June 1992.

       [2] Gerich, E., "Guidelines for management of IP Address Space", RFC
           1466, Merit, May 1993.

       [3] Topolcic, C., "Schedule for IP Address Space Management
           Guidelines", RFC 1367, CNRI, October 1992.

       [4] Rekhter, Y., and T. Li, "An Architecture for IP Address
           Allocation with CIDR", Work in Progress, January 1993.

       [5] Rekhter, Y., and C. Topolcic, "Exchanging Routing Information
           across Provider/Subscriber Boundaries in CIDR environment", Work
           in Progress, February 1993.

    Security Considerations

       Security issues are not discussed in this memo.

    Author's Address

       Christian Huitema
       INRIA, Sophia-Antipolis
       2004 Route des Lucioles
       BP 109
       F-06561 Valbonne Cedex
       France

       Phone: +33 93 65 77 15
       EMail: Christian.Huitema@MIRSA.INRIA.FR

    IAB                                                             [Page 2]