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Network Working Group                                         Jon PostelRequest for Comments: 890                                            ISI                                                           February 1984Exterior Gateway Protocol Implementation ScheduleStatus of this Memo   This memo is a policy statement on the implementation of the Exterior   Gateway Protocol in the Internet.  This is an official policy   statement of ICCB and DARPA.The Current Situation   Currently the Internet has a number of smart gateways and a number of   dumb gateways.  The smart gateways dynamically exchange routing   information among themselves using the Gateway Gateway   Protocol (GGP) [3].  The dumb gateways do not exchange routing   information dynamically.   The dumb gateways must be listed in the smart gateway routing tables,   and changes in dumb gateways status (e.g., adding new dumb gateways)   in the smart gateways tables requires human intervention.   The amount of routing traffic between smart gateways depends on the   number of smart gateways and the total number of networks.  Since   dumb gateways typically connect a single network at the edge of the   Internet, there is typically one more network in the routing table   for each dumb gateway.   Gateways that connect a single network to the edge of the Internet   may be called "stub" gateways.   The current GGP procedures used by the smart gateways are at the   limits of their capacity.  A significant change to these procedures   is urgently required.  This is difficult to perform because the smart   gateways are maintained by several different groups, and because it   is difficult to isolate a subset of these gateways for testing new   procedures.The Future Situation   In the future, as it is currently envisioned, there will be a number   of co-equal autonomous systems of gateways.  Each as will have its   own private internal procedures for maintaining routing information,   perhaps via an Interior Gateway Protocol (IGP).  The smartness of a   gateway will be the smartness of the IGP used in the autonomous   system the gateway participates in.  Some gateways of each autonomous   system will exchange routing informations with some gateways of other   autonomous systems via an Exterior Gateway Protocol (EGP) [2].Postel                                                          [Page 1]

RFC 890                                                    February 1984EGP Implementation Schedule   The factoring of the old set of smart gateways into a number of   autonomous systems allows more flexibility for the development and   testing of improved routing procedures.  Different autonomous systems   can adopt different routing procedures internally, as long as they   communicate with other autonomous systems via the EGP.The Transition Situation   The first step in the transition from the current situation to the   future situation is the replacement of all dumb gateways with   gateways that implement at least a subset of the EGP.      This subset is called the "Stub Exterior Gateway Protocol", and is      described inRFC-888 [1].   The second step is to factor the existing smart gateways into   autonomous systems.  The gateways programmed and maintained by   different groups will become distinct autonomous systems.  As things   are, this will result in one fairly large autonomous system and three   or four small autonomous systems.  At this step the large autonomous   system will be referred to as the "core" autonomous system.  All   other autonomous systems will be stubs attached to this core via EGP.   The third step is to specify the full EGP protocol, and to allow a   rich connectivity between co-equal autonomous systems.Policy Statement   After 1-Aug-84 there shall be no dumb gateways in the Internet.   Every gateway must be a member of some autonomous system.  Some   gateway of each autonomous system must exchange routing information   with some gateway of the core autonomous system using the Exterior   Gateway Protocol.Implication   If you have a dumb gateway now, you should start doing something   today to get it upgraded to, or replaced by, an EGP gateway.Help Available   There may be a gateway you can use already developed by someone.   People at the following places are working on EGP gateways:  BBN,   MIT, Linkabit, ISI, Honeywell, and Symbolics.  For more information   send a message to Joyce Reynolds at mailbox "JKReynolds@USC-ISIF".   There are plans to provide EGP functionality in Berkeley 4.2 Unix.Postel                                                          [Page 2]

RFC 890                                                    February 1984EGP Implementation Schedule   Berkeley has indicated an intention to have EGP capability available   in the standard release of 4.2 Unix before the cut off date for dumb   gateways.   The is a mailing list for EGP implementers called "egp-people".  To   get on or off this list send a message to the mailbox   "egp-people-request@BBN-UNIX".   There is a EGP testing program available on TOPS20.  For information   about using it send a message to Jim Mathis at mailbox   "Mathis@SRI-KL".   If you need an autonomous system number send a request to Joyce   Reynolds at mailbox "JKReynolds@USC-ISIF".References   [1]  Seamonson, L., and E. Rosen, "Stub Exterior Gateway Protocol",RFC-888, BBN Communications Company, January 1984.   [2]  Rosen, E., "Exterior Gateway Protocol",RFC-827, Bolt Beranek        and Newman, October 1982.   [3]  Hinden, R., and A. Sheltzer, "The DARPA Internet Gateway",RFC-823, Bolt Beranek and Newman, September 1982.Postel                                                          [Page 3]