Content

| Overview

Routing protocols can be classified in many ways. It depends on where they are used in relationship to the enterprise. Protocols that run inside an enterprise are called interior gateway protocols (IGPs). Examples of IGPs include RIP versions 1 and 2, IGRP, EIGRP, and OSPF. Protocols that run outside an enterprise, or between autonomous systems (ASs), are called exterior gateway protocols (EGPs). Typically, EGPs are used to exchange routing information between Internet Service Providers (ISPs), or in some cases between a customer's AS and the provider's network. Border Gateway Protocol, version 4 (BGP4), is the most common EGP and is considered the Internet standard.

This module provides an overview of the different types of autonomous systems and then focuses on basic BGP operation, including BGP neighbor negotiation. The module also looks at how to use the Cisco IOS to configure BGP and verify its operation. Finally, it examines BGP peering and the BGP routing process.