Prerequisites: CCNP level skills.
Topology
Note!
All routers are configured as per topology diagram (pic. 1) and loopback advertised into BGP.
Pic. 1 - Topology Diagram.
Icons designed by: Andrzej Szoblik - http://www.newo.pl
Task 1
Configure BGP in AS 40, so that R2 prefers path through AS 13 towards 172.16.104.0/24.
Lab Solution
Task 1
Configure BGP in AS 40, so that R2 prefers path through AS 13 towards 172.16.104.0/24.
Pic. 2 - R2's BGP Table.
R2 prefers shorter path (through AS 40) to longer one (AS 13 and AS 40)
R4 Configuration:
!
ip prefix-list Lo0 seq 5 permit 172.16.104.0/24
!
route-map PREPEND permit 10
match ip address prefix-list Lo0
set as-path prepend 40 40 40
!
route-map PREPEND permit 999
!
match ip address prefix-list Lo0
set as-path prepend 40 40 40
!
route-map PREPEND permit 999
!
router bgp 40
no synchronization
bgp router-id 172.16.104.4
bgp log-neighbor-changes
network 172.16.104.0 mask 255.255.255.0
network 172.16.144.0 mask 255.255.255.0
neighbor 10.1.14.1 remote-as 13
neighbor 10.1.24.2 remote-as 20
neighbor 10.1.24.2 route-map PREPEND out
no auto-summary
no synchronization
bgp router-id 172.16.104.4
bgp log-neighbor-changes
network 172.16.104.0 mask 255.255.255.0
network 172.16.144.0 mask 255.255.255.0
neighbor 10.1.14.1 remote-as 13
neighbor 10.1.24.2 remote-as 20
neighbor 10.1.24.2 route-map PREPEND out
no auto-summary
!
Verification:
Pic. 3 - R2's BGP Table.
