Core Router, Border Gateway Protocol Bgp-4 Technology

With the increasing development of Internet applications,high-speed core router has become the researching emphasis and hot technology of network area. As core router may be used in all kinds of environments,it must implement multiple routing protocols,including RIP,OSPF,IS-IS,BGP and other Interior or Exterior routing protocols. BGP-4 is a widely used Border Gateway Routing protocol in TCP/IP networks.The thesis presents the implementation technology of BGP-4 system over high-speed core router.Running over TCP,BGP-4 is a kind of Path-Vector routing protocol. It has the advantages of Distance-Vector and Link-State routing protocols. BGP routers exchange routing information upon initial data exchange,then with the incremental updates,only when the routing table changes,the peers send the portion of their routing table that has been changed. BGP routers do not send regularly scheduled routing update.Being a complicated dynamic routing protocol,BGP's performance is the critical problem under the situation of keeping many peer relations and big routing table. The implementation of our software has been divided to several models. Route aggregation,routing redistribution and some other routing policies are the key abilities and must be implemented for BGP-4. The paper also discusses these routing polices deeply.Having been used and tested in the environment of "YH 9108" core-router,our BGP-4 system is considered to have high stability,good interoperation and high performance. The realization of BGP-4 system provides a powerful technology for research and development of future higher-speed routers.