Cisco IOS Cookbook, 2nd Edition

Redistributing Routes with BGP

Problem

You want to redistribute routes between an IGP and BGP.

Solution

When connecting two or more IGPs using BGP, you sometimes need to configure redistribution between the IGP and BGP on both routers. To make the example more interesting, we will assume that we need to connect an EIGRP network to an OSPF network using a pair of BGP routers.

The first router redistributes routes from BGP into OSPF:

Router1#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router1(config)#router ospf 100
Router1(config-router)#network 172.26.0.0 0.0.255.255 area 0
Router1(config-router)#redistribute bgp 65500 metric 500 subnets
Router1(config-router)#exit
Router1(config)#router bgp 65500
Router1(config-router)#neighbor 192.168.1.5 remote-as 65520
Router1(config-router)#network 172.26.0.0
Router1(config-router)#exit
Router1(config)#end
Router1#

And this is the configuration for the router that redistributes BGP routes into EIGRP:

Router2#configure terminal
Enter configuration commands, one per line.  End with CNTL/Z.
Router2(config)#router eigrp 99
Router2(config-router)#network 172.25.0.0
Router2(config-router)#redistribute bgp 65520 metric 500 10 255 1 1500
Router2(config-router)#exit
Router2(config)#router bgp 65520
Router2(config-router)#neighbor 192.168.1.6 remote-as 65500
Router2(config-router)#network 172.25.0.0
Router2(config-router)#exit
Router2(config)end
Router2#

Discussion

Before we say anything about this recipe, we need to stress ...