References

   [1] Rekhter Y., and T. Li, "A Border Gateway Protocol 4 (BGP-4), RFC
       1771, T.J. Watson Research Center, IBM Corp., cisco Systems,
       March 1995.

   [2] Braun, H-W., "Models of Policy Based Routing", RFC 1104,
       Merit/NSFNET, June 1989.

   [3] Fuller, V., Li, T., Yu, J., and K. Varadhan, "Supernetting:  an
       Address Assignment and Aggregation Strategy", RFC1519, BARRNet,
       cisco, MERIT, OARnet, September 1993.