Chapter 8. Cisco Router Configuration for BGP

Table of Contents
Static Default Route
Floating Static Default Route
Loopback Interfaces
BGP Router Process
Internal Neighbors
External Neighbor
Auto Summary
Static Route Origination
Semi-Dynamic Route Origination
Dynamic Route Origination
Pull Up Routes
Preventing Transit
Filtering Routes Originated
Filtering Routes Accepted
Setting MEDs
HSRP (Hot Standby Router Protocol)
Originating a BGP Default Route

The process of router configuration can be thought of much like programming. This chapter details the fundamental building blocks of BGP router configuration. Task-oriented fragments of router configurations are given in this chapter with some advice on applicability and interaction with other fragments. Links are provided to the policy chapter as appropriate. No complete router configurations are given, but the following scenario chapters will contain complete configs.

   Assume you know
      Details of setting up your serial interfaces (e.g. B8ZS, etc.)
      See Ballew or cisco docs if not.

Static Default Route

This configuration directs all traffic that has no other explicit route toward an interface or host.

If reliability is a concern, static default routes should be used only in routers that have one path to reach all exits from your AS. See the section called Exit Selection and Static Default Routes in Chapter 7 for details.

Interface Destination
       ip route Serial0/0

The interface destination form is used for point-to-point links because it avoids having to know the IP address of the remote end of the link (typically your ISP).

Host Destination
       ip route

The host destination form is used on multi-access networks (e.g. Ethernet).

Copyright © 1999-2000 by Robert A. Van Valzah