Goal :
- Manipulate outbound traffic from R1 to network 3.3.3.0/24 goes through R2>R4>R3. Normal BGP routing table should goes through R3 directly.
- Make sure outbound traffic from R1 to network 44.44.44.0/24 will always goes through R3>R4
Configuration :
Create route-map for match ip access-list & set weight attribute.
R1#
route-map toR2 permit 10
match ip address 1
set weight 500
exit
route-map toR2 permit 20
exit
route-map toR3 permit 10
match ip address 2
set weight 65535
exit
route-map toR3 permit 20
exit
Create access-list
R1#
access-list 1 permit 3.3.3.0 0.0.0.255
access-list 2 permit 44.44.44.0
BGP router configuration
R1#
router bgp 12
no synchronization
bgp log-neighbor-changes
network 1.1.1.0 mask 255.255.255.0
network 11.11.11.0 mask 255.255.255.0
network 192.168.12.0
network 192.168.13.0
neighbor 192.168.12.2 remote-as 12
neighbor 192.168.12.2 route-map toR2 in
neighbor 192.168.13.3 remote-as 34
neighbor 192.168.13.3 route-map toR3 in
no auto-summary
Verification :
R1# sh ip bgp
*>i3.3.3.0/24 192.168.24.4 0 100 500 34 i
-> Weight 500
* 192.168.13.3 0 0 34 i
* i44.44.44.0/24 192.168.24.4 0 100 0 34 i
*> 192.168.13.3 65535 34 i
-> Highest weight 65535