A BGP/IDRP Route Server alternative to a full mesh routing (RFC1863)
Original Publication Date: 1995-Oct-01
Included in the Prior Art Database: 2019-Feb-12
Internet Society Requests For Comment (RFCs)
This document describes the use and detailed design of Route Servers for dissemination of routing information among BGP/IDRP speaking routers. This memo defines an Experimental Protocol for the Internet community.
Network Working Group D. Haskin Request For Comments: 1863 Bay Networks, Inc. Category: Experimental October 1995
A BGP/IDRP Route Server alternative to a full mesh routing
Status of this Memo
This memo defines an Experimental Protocol for the Internet community. This memo does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited.
This document describes the use and detailed design of Route Servers for dissemination of routing information among BGP/IDRP speaking routers.
The intention of the proposed technique is to reduce overhead and management complexity of maintaining numerous direct BGP/IDRP sessions which otherwise might be required or desired among routers within a single routing domain as well as among routers in different domains that are connected to a common switched fabric (e.g. an ATM cloud).
Current deployments of Exterior Routing protocols, such as the Border Gateway Protocol [BGP4] and the adaptation of the ISO Inter-Domain Routing Protocol [IDRP], require that all BGP/IDRP routers, which participate in inter-domain routing (border routers) and belong to the same routing domain, establish a full mesh connectivity with each other for purpose of exchanging routing information acquired from other routing domains. In large routing domains the number of intra- domain connections that needs to be maintained by each border route can be significant.
In addition, it may be desired for a border router to establish routing sessions with all border routers in other domains which are reachable via a shared communication media. We refer to routers that are directly reachable via a shared media as adjacent routers. Such direct peering allows a router to acquire "first hand" information about destinations which are directly reachable through adjacent routers and select the optimum direct paths to these destinations. Establishment of BGP/IDRP sessions among all adjacent border routers would result in a full mesh routing connectivity. Unfortunately for
Haskin Experimental [Page 1]
RFC 1863 A BGP/IDRP Route Server October 1995
a switched media as ATM, SMDS or Frame Relay network which may inter-connect a large number of routers, due to the number of connections that would be needed to maintain a full mesh direct peering between the routers, makes this approach impractical.
In order to alleviate the "full mesh" problem, this paper proposes to use IDRP/BGP Route Servers which would relay external routes with all of their attributes between client routers. The clients would maintain IDRP/BGP sessions only with the assigned route servers (sessions with more than one server would be needed if redundancy is desired). All routes that are received from a client router would be propagated to other clients by the Route Server. Since all external routes and their attributes are relayed unmodified between the client routers, the client routers woul...