Lab 139 - BGP Soft Reconfiguration

Prerequisites: CCNP level skills.

Topology

Pic. 1 - Topology Diagram.

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

Task 1
Configure R5 in such way, that if BGP in R3 does not support 'Route Refresh' message, it can still apply inbound policy without asking R5 to re-send their BGP prefixes.

Solution

Task 1

Configure R5 in such way, that if BGP in R3 does not support 'Route Refresh' message, it can still apply inbound policy without asking R5 to re-send their BGP prefixes.

Pic. 2 - BGP Before Applying Configuration.

R5 Configuration:

!

router bgp 50
 no synchronization
 bgp router-id 172.16.105.5
 bgp log-neighbor-changes
 network 172.16.105.0 mask 255.255.255.0
 neighbor 10.1.35.3 remote-as 123
 neighbor 10.1.35.3 soft-reconfiguration inbound
 no auto-summary

!

Verfication:

Pic. 3 - BGP After Applying Configuration.

Notice!
This command creates the exact copy of the BGP table. This causes high memory utilization but allows to apply inbound filtering on R5 without tearing down the session if the Route-Refresh messages are not supported on R5.