48. Routing reflector for BGP configuration experiment
1. Route reflector analysis
How the route reflector works:
RR routes received from EBGP are reflected to clients and non-clients
RR routes received from clients are reflected to clients, EBGP neighbors, and non-clients
RR routes received from non-clients are reflected only to clients and EBGP neighbors, not to non-clients
2. Experimental topology
3. Basic configuration
R1 configurations
interface Loopback0
ip address 1.1.1.1 255.255.255.0
interface Serial0/0
ip address 12.1.1.1 255.255.255.0
router bgp 1
no synchronization
bgp router-id 1.1.1.1
network 1.1.1.0 mask 255.255.255.0
neighbor 12.1.1.2 remote-as 2
no auto-summary
R2 configuration
interface Loopback0
ip address 2.2.2.2 255.255.255.0
interface Serial0/0
ip address 12.1.1.2 255.255.255.0
interface Serial0/1
ip address 23.1.1.2 255.255.255.0
router ospf 110
router-id 2.2.2.2
network 2.2.2.0 0.0.0.255 area 0
network 23.1.1.0 0.0.0.255 area 0
router bgp 2
no synchronization
bgp router-id 2.2.2.2
neighbor 3.3.3.3 remote-as 2
neighbor 3.3.3.3 update-source Loopback0
neighbor 3.3.3.3 next-hop-self
neighbor 12.1.1.1 remote-as 1
no auto-summary
R3 configuration
interface Loopback0
ip address 3.3.3.3 255.255.255.0
interface Serial0/0
ip address 34.1.1.3 255.255.255.0
interface Serial0/1
ip address 23.1.1.3 255.255.255.0
router ospf 110
router-id 3.3.3.3
network 3.3.3.0 0.0.0.255 area 0
network 23.1.1.0 0.0.0.255 area 0
network 34.1.1.0 0.0.0.255 area 0
router bgp 2
no synchronization
bgp router-id 3.3.3.3
neighbor 2.2.2.2 remote-as 2
neighbor 2.2.2.2 update-source Loopback0
neighbor 4.4.4.4 remote-as 2
neighbor 4.4.4.4 update-source Loopback0
no auto-summary
R4 configuration
interface Loopback0
ip address 4.4.4.4 255.255.255.0
interface Serial0/0
ip address 34.1.1.4 255.255.255.0
router ospf 110
router-id 4.4.4.4
network 4.4.4.0 0.0.0.255 area 0
network 34.1.1.0 0.0.0.255 area 0
router bgp 2
no synchronization
bgp router-id 4.4.4.4
neighbor 3.3.3.3 remote-as 2
neighbor 3.3.3.3 update-source Loopback0
no auto-summary
4. Problems caused by horizontal segmentation
5. Configure route reflector to solve horizontal segmentation
R3 configuration
router bgp 2
neighbor 2.2.2.2 route-reflector-client
neighbor 4.4.4.4 route-reflector-client
