System information

Configuring BGP
12-1
Overview
This chapter describes how to configure Border Gateway Protocol (BGP) for the BSR
64000™ system using the command line interface (CLI). For a complete description
of the CLI commands discussed in this chapter, refer to the BSR 64000 Command
Reference Guide. This chapter discusses the following topics:
• About BGP
• Configuring Basic BGP Connectivity
• Configuring Advanced BGP Connectivity
• Configuring Global BGP Tasks
• Configuring BGP Update Flows
• Configuring Routing Policy
• Handling Access Lists
• Creating a Community List
• Redistributing Routes into BGP
About BGP
BGP, an Exterior Gateway Protocol (EGP) allows you to set up an inter-domain
routing system that automatically guarantees the loop-free exchange of routing
information between autonomous systems (ASs). An AS is a set of routers that use a
single routing policy running under a single technical administration. An AS runs
Interior Gateway Protocols (IGPs) such as Routing Information Protocol (RIP), and
Open Shortest Path First (OSPF) within its boundaries.
BGP is used by almost all routers to connect ASs to network backbones. With BGP,
each route comprises a network number, a list (AS path) of ASs that information
passed through, and a list of other path attributes. A BGP system exchanges network
reachability information with other BGP systems, including AS path information.
This information allows routing loops to be pruned and AS-level policy decisions to
be enforced.