Simulating IBGP

Practical 6: Simulating IBGP
Advance Computer Network MSc IT Part 1 Practicals
Network Topology

Internal BGP
Configuring IP addresses on all the interfaces
Router R1

R1(config)#int f1/0
R1(config-if)#ip add 192.168.12.1 255.255.255.0
R1(config-if)#no shut
R1(config-if)#exit
R1(config)#int f1/1
R1(config-if)#ip add 192.168.13.1 255.255.255.0
R1(config-if)#no shut
R1(config-if)#exit
R1(config)#int loopback0
R1(config-if)#ip add 1.1.1.1 255.255.255.0
R1(config-if)#exit
R1(config)#int loopback1
R1(config-if)#ip add 11.11.11.11 255.255.255.0
R1(config-if)#exit
R1(config)#

Router R2

R2#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R2(config)#int f1/0
R2(config-if)#ip add 192.168.13.2 255.255.255.0
R2(config-if)#no shut
R2(config-if)#exit
R2(config)#int f1/1
R2(config-if)#ip add 192.168.34.1 255.255.255.0
R2(config-if)#no shut
R2(config-if)#exit
R2(config)#int loopback0
R2(config-if)#ip add 3.3.3.3 255.255.255.0
R2(config-if)#exit
R2(config)#int loopback1
R2(config-if)#int loopback0
R2(config-if)#no ip add
R2(config-if)#int loopback0
R2(config-if)#ip add 2.2.2.2 255.255.255.0
R2(config-if)#exit
R2(config)#int loopback1
R2(config-if)#ip add 22.22.22.22 255.255.255.0
R2(config-if)#

Router R3

R3>en
R3#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R3(config)#int f1/1
R3(config-if)#ip add 192.168.34.2 255.255.255.0
R3(config-if)#no shut
R3(config-if)#exit
R3(config)#int f1/0
R3(config-if)#ip add 192.168.24.2 255.255.255.0
R3(config-if)#no shut
R3(config-if)#exit
R3(config)#int loopback0
R3(config-if)#ip add 3.3.3.3 255.255.255.0
R3(config-if)#exit
R3(config)#int loopback1
R3(config-if)#ip add 33.33.33.33 255.255.255.0
R3(config-if)#exit
R3(config)#

Router R4

R4(config)#int f1/1
R4(config-if)#ip add 192.168.24.1 255.255.255.0
R4(config-if)#no shut
R4(config-if)#exit
R4(config)#int f1/0
R4(config-if)#ip add 192.168.12.2 255.255.255.0
R4(config-if)#no shut
R4(config-if)#exit
R4(config)#int loopback0
R4(config-if)#ip add 4.4.4.4 255.255.255.0
R4(config-if)#exit
R4(config)#int loopback1
R4(config-if)#ip add 44.44.44.44 255.255.255.0
R4(config-if)#exit
R4(config)#

Setting up OSPF for reachability
Router R1

R1(config)#router ospf 1
R1(config-router)#network 192.168.12.0 0.0.0.255 area 0
R1(config-router)#network 192.168.13.0 0.0.0.255 area 0
R1(config-router)#network 1.1.1.0 0.0.0.255 area 0
R1(config-router)#

Router R2

R2(config)#router ospf 1
R2(config-router)#network 192.168.13.0 0.0.0.255 area 0
R2(config-router)#network 192.168.13.0 0.0.0.255 area 0
R2(config-router)#network 192.168.34.0 0.0.0.255 area 0
R2(config-router)#network 192.168.13.0 0.0.0.255 area 0
R2(config-router)#network 2.2.2.2 0.0.0.255 area 0

Router R3

R3(config)#router ospf 1
R3(config-router)#network 192.168.34.0 0.0.0.255 area 0
R3(config-router)#network 192.168.24.0 0.0.0.255 area 0
R3(config-router)#network 192.168.24.0 0.0.0.255 area 0

R4

R4(config)#router ospf 1
R4(config-router)#network 192.168.12.0 0.0.0.255 area 0
R4(config-router)#network 192.168.24.0 0.0.0.255 area 0
R4(config-router)#network 192.168.24.0 0.0.0.255 area 0

Configuring IBGP
Router R1

R1(config)#router bgp 1234
R1(config-router)#neighbor 4.4.4.4 remote-as 1234
R1(config-router)#neighbor 4.4.4.4 remote-as update-source loopback 0
R1(config-router)#neighbor 4.4.4.4 update-source loopback 0
R1(config-router)#network 11.11.11.0 mask 255.255.255.0
R1(config-router)#neighbor 2.2.2.2 remote-as 1234
R1(config-router)#neighbor 2.2.2.2 update-source loopback0
R1(config-router)#neighbor 3.3.3.3  remote-as 1234
R1(config-router)#neighbor 3.3.3.3  update-source loopback0

Router R2

R2(config)#router bgp 1234
R2(config-router)#neighbor 1.1.1.1 remote-as 1234
R2(config-router)#neighbor 1.1.1.1 update-source loopback 0
R2(config-router)#neighbor 3.3.3.3 remote-as 1234
R2(config-router)#neighbor 3.3.3.3 update-source loopback 0
R2(config-router)#neighbor 4.4.4.4 remote-as 1234
R2(config-router)#neighbor 4.4.4.4 update-source loopback 0
R2(config-router)#network 22.22.22.0 mask 255.255.255.0
R2(config-router)#exit
R2(config)#

Router R3

R3(config)#router bgp 1234
R3(config-router)#neighbor 1.1.1.1 remote-as 1234
R3(config-router)#neighbor 1.1.1.1 update-source loopback 0
R3(config-router)#neighbor 2.2.2.2 remote-as 1234
R3(config-router)#neighbor 2.2.2.2 update-source loopback 0

R3(config-router)#neighbor 3.3.3.3 remote-as 1234
% Cannot configure the local system as neighbor
R3(config-router)#neighbor 4.4.4.4 remote-as 1234
R3(config-router)#neighbor 4.4.4.4 update-source loopback 0
R3(config-router)#network 33.33.33.0 mask 255.255.255.0
R3(config-router)#exit
R3(config)#

Router R4

R4(config)#router bgp 1234
R4(config-router)#neighbor 1.1.1.1 remote-as 1234
R4(config-router)#neighbor 1.1.1.1 update-source loopback 0
R4(config-router)#neighbor 2.2.2.2 remote-as 1234
R4(config-router)#neighbor 2.2.2.2 update-source loopback0
R4(config-router)#neighbor 3.3.3.3 remote-as 1234
R4(config-router)#neighbor 3.3.3.3 update-source loopback 0
R4(config-router)#

Verifying the network