Lab 141 - BGP Next-Hop Address Tracking

Prerequisites: CCNP level skills.

Note!
Configuration from Lab 140.

Topology

Pic. 1 - Topology Diagram.

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

Task 1
Configure R3 in such a way that the interval between full table walks is 10 seconds (not 5 which is default).

Solution

Task 1

Configure R3 in such a way that the interval between full table walks is 10 seconds (not 5 which is default).

R3 Configuration:

!

R3#show run | s router bgp
router bgp 100
 no synchronization
 bgp router-id 172.16.103.3
 bgp log-neighbor-changes
 bgp nexthop trigger delay 10
 network 172.16.103.0 mask 255.255.255.0
 neighbor 10.1.35.5 remote-as 50
 neighbor 172.16.101.1 remote-as 100
 neighbor 172.16.101.1 update-source Loopback0
 neighbor 172.16.102.2 remote-as 100
 neighbor 172.16.102.2 update-source Loopback0
 neighbor 172.16.104.4 remote-as 100
 neighbor 172.16.104.4 update-source Loopback0
 no auto-summary

!

Note!
The BGP Support for Next-Hop Address Tracking feature is enabled by default when a supporting Cisco IOS software image is installed. BGP next-hop address tracking is event driven. BGP prefixes are automatically tracked as peering sessions are established. Next-hop changes are rapidly reported to the BGP routing process as they are updated in the RIB. This optimization improves overall BGP convergence by reducing the response time to next-hop changes for routes installed in the RIB. When a bestpath calculation is run in between BGP scanner cycles, only next-hop changes are tracked and processed.


Source:
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t14/feature/guide/gt_bnht.html