FIGURE 8 . 1 6 Redistributing routes into BGP

FIGURE 8 . 1 6 Redistributing routes into BGP
In order to redistribute this segment, we will need to use connected as the protocol for
redistribution. This will redistribute all of the connected interfaces on R3 into BGP. With
all of this in mind, let’s enable BGP on R2 and R3 and configure their peer relationships
with each other:
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router bgp 100
R2(config-router)#neighbor 3.3.3.3 remote-as 200
R2(config-router)#neighbor 3.3.3.3 update-source Lo0
R2(config-router)#neighbor 3.3.3.3 ebg-multihop
R2(config-router)#^Z
R2#
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router bgp 200
AS 200
AS 100
20.20.20.0 /30
.1
.1
.1
.1
.1
S0
S1
.2
.2
S0
S0
10.10.10.0 /30
E1
E0
E0
192.168.24.0 /24
192.168.200.0 /24
192.168.100.0 /24 R3
R1
R2
272 Chapter 8  Border Gateway Protocol
R3(config-router)#neighbor 2.2.2.2 remote-as 100
R3(config-router)#neighbor 2.2.2.2 update-source Lo0
R3(config-router)#neighbor 2.2.2.2 ebg-multihop
R3(config-router)#^Z
R3#
We now need to configure redistribution on R2 and R3:
R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#router bgp 100
R2(config-router)#redistribute eigrp 100
R2(config-router)#^Z
R2#
R3#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R3(config)#router bgp 200
R3(config-router)#redistribute connected
R3(config-router)#^Z
R3#
By using the redistribute command, we have injected all of the EIGRP routes that R2
knows about into BGP. We have also injected the connected interface addresses from R3
into BGP. The problem you will encounter by just redistributing routes into BGP is that
there may be some routes you do not want BGP to know about. Filtering could be used to
filter out the routes that you do not want BGP to know about. We cover this concept in
detail in Chapter 9.
You should now have a good understanding of how to configure the basic components of
BGP. We will cover the configurations of the more advanced topics of BGP in Chapter 9. Now
that we have BGP configured, we need to be able to verify that it is working properly and, if any
issues occur, be able to troubleshoot them.