Cisco Systems 78-11741-02 RIP and Eigrp Redistribution Examples, Simple Redistribution Example

Configuring IP Routing Protocol-Independent Features

IP Routing Protocol-Independent Configuration Examples

RIP and EIGRP Redistribution Examples

This section provides a simple RIP redistribution example and a complex redistribution example between Enhanced IGRP (EIGRP) and BGP.

Simple Redistribution Example

Consider a WAN at a university that uses RIP as an interior routing protocol. Assume that the university wants to connect its WAN to a regional network, 172.16.0.0, which uses Enhanced IGRP (EIGRP) as the routing protocol. The goal in this case is to advertise the networks in the university network to the routers on the regional network. The commands for the interconnecting router are listed in the example that follows:

router eigrp 1 network 172.16.0.0 redistribute rip

default-metric 10000 100 255 1 1500 distribute-list 10 out rip

In this example, the router global configuration command starts an EIGRP routing process. The network router configuration command specifies that network 172.16.0.0 (the regional network) is to send and receive EIGRP routing information. The redistribute router configuration command specifies that RIP-derived routing information be advertised in the routing updates. The default-metricrouter configuration command assigns an EIGRP metric to all RIP-derived routes. The distribute-listrouter configuration command instructs the Cisco IOS software to use access list 10 (not defined in this example) to limit the entries in each outgoing update. The access list prevents unauthorized advertising of university routes to the regional network.

Complex Redistribution Example

The most complex redistribution case is one in which mutual redistribution is required between an IGP (in this case EIGRP) and BGP.

Suppose that BGP is running on a router somewhere else in autonomous system 50000 and that the BGP routes are injected into EIGRP routing process 1. You must use filters to ensure that the proper routes are advertised. The example configuration for router R1 illustrates use of access filters and a distribution list to filter routes advertised to BGP neighbors. This example also illustrates configuration commands for redistribution between BGP and EIGRP.

!Configuration for router R1: router bgp 50000

network 172.18.0.0

neighbor 192.168.10.1 remote-as 2 neighbor 192.168.10.15 remote-as 1 neighbor 192.168.10.24 remote-as 3 redistribute eigrp 1 distribute-list 1 out eigrp 1

!All networks that should be advertised from R1 are controlled with access lists:

access-list 1 permit 172.18.0.0 access-list 1 permit 172.16.0.0 access-list 1 permit 172.17.0.0

router eigrp 1 network 172.18.0.0 network 192.168.10.0

Cisco IOS IP Configuration Guide

IPC-383