Monday, May 9, 2011

Lab 130 - BGP Next-Hop using Route-map

Prerequisites: CCNP level skills.

Note!
Use the configuration from Lab 129 except for 'next-hop-self' command.

Topology

Pic. 1 - Topology Diagram.
Icons designed by: Andrzej Szoblik - http://www.newo.pl

Task 1
Similarly to the lab 129, deal with the next hop on R1, R2 and R3, but do not use 'next-hop-self' command or redistribution into IGP.

Solution

Task 1
Similarly to the lab 129, deal with the next hop on R1, R2 and R3, but do not use 'next-hop-self' command or redistribution into IGP.
R1 Configuration:
!
route-map SET_NEXT_HOP permit 10
 set ip next-hop 10.1.13.1
!
router bgp 123
 no synchronization
 bgp router-id 172.16.101.1
 bgp log-neighbor-changes
 network 172.16.101.0 mask 255.255.255.0
 neighbor 10.1.13.3 remote-as 123
 neighbor 10.1.13.3 route-map SET_NEXT_HOP out
 neighbor 10.1.14.4 remote-as 40
 no auto-summary
!

Then, 'clear ip bgp * out'

Notice!
While configuring the 'set ip next-hop 10.1.13.1' we get the warning which can be ignored. We know what we're doing after all ;)

Pic. 2 - Warning.

R2 Configuration:
!
route-map SET_NEXT_HOP permit 10
 set ip next-hop 10.1.23.2
!
router bgp 123
 no synchronization
 bgp router-id 172.16.102.2
 bgp log-neighbor-changes
 network 172.16.102.0 mask 255.255.255.0
 neighbor 10.1.23.3 remote-as 123
 neighbor 10.1.23.3 route-map SET_NEXT_HOP out
 neighbor 10.1.24.4 remote-as 40
 no auto-summary
!

R3 Configuration:
!
route-map SET_NEXT_HOP_R2 permit 10
 set ip next-hop 10.1.23.3
!
route-map SET_NEXT_HOP_R1 permit 10
 set ip next-hop 10.1.13.3
!
router bgp 123
 no synchronization
 bgp router-id 172.16.103.3
 bgp log-neighbor-changes
 network 172.16.103.0 mask 255.255.255.0
 neighbor 10.1.13.1 remote-as 123
 neighbor 10.1.13.1 route-reflector-client
 neighbor 10.1.13.1 route-map SET_NEXT_HOP_R1 out
 neighbor 10.1.23.2 remote-as 123
 neighbor 10.1.23.2 route-reflector-client
 neighbor 10.1.23.2 route-map SET_NEXT_HOP_R2 out
 neighbor 10.1.35.5 remote-as 50
 no auto-summary
!

Verification:
This time let's check if R1 and R2 have the best path to prefix from AS 50.

Pic. 3 - AS 50 Prefix on R1.

 Pic. 3 - AS 50 Prefix on R2.