Chapter 14. Understanding Border Gateway Protocol Version 4 (BGP-4)

This chapter covers the following key topics about Border Gateway Protocol version 4 (BGP-4):

BGP-4 protocol specification and functionality

Neighbor relationships

Advertising routes


Receiving routes

Policy control

Scaling IBGP networks (route reflectors and confederations)

Best-path calculation

An autonomous system (AS) is a set of devices under common administration. Between two or more autonomous systems, the Border Gateway Protocol advertises network reachability information. The Internet backbone relies solely on BGP to announce and receive IP prefixes, and the only routing protocol that runs between two autonomous systems is BGP.

Before BGP, ...

Get Troubleshooting IP Routing Protocols now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.