Lab 120 - BGP Default Route Advertisement

Prerequisites: CCNP level skills.

Note!
Topology from Lab 118.

Topology

Pic. 1 - Topology Diagram.

Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1
Configure R5 so that it advertises the default route. This advertisement should be propagated to all potential BGP peers.

Solution

Task 1

Configure R5 so that it advertises the default route. This advertisement should be propagated to all potential BGP peers.

R5 Configuration:

!

ip route 0.0.0.0 0.0.0.0 Null0
!

router bgp 50
 no synchronization
 bgp router-id 172.16.105.5
 bgp log-neighbor-changes
 network 0.0.0.0
 network 172.16.105.0 mask 255.255.255.0
 neighbor 10.1.35.3 remote-as 30
 no auto-summary

!

Verification:

Pic. 2 - R3's BGP Table.

Notice!
In order for R5 to advertise the default route to all BGP peers, one must exist in the routing table. That's why I have configured a default route pointing to null0 and advertised it using the 'network' statement. Alternatively, I could redistribute static routes into BGP.