The lab is from my friend, Andrey, you can find the lab objective here:
http://eccentric.mae.cornell.edu/~andrey/labs/BGP%20Dual-connected%20AS%20with%20OSPF.pdf
R1: 1841-1
R2: 2651-1
R3: 2651-2
R4: 1841-2
R5: 3825-1
Subnet at segment between R1 and R2: 192.168.1.0/24
Subnet at segment between R2 and R3: 192.168.2.0/24
Subnet at segment between R3 and R4: 192.168.3.0/24
subnet between R1 and R5: 100.10.10.0/24
subnet between R2 and R5: 100.20.20.0/24
R5 has a loopback123: 123.123.123.123 /24
R5 configuration
3825-1#sh run | s router bgp
router bgp 1
no synchronization
bgp log-neighbor-changes
network 123.123.123.0 mask 255.255.255.0
network 172.16.1.1 mask 255.255.255.255
neighbor 172.16.1.2 remote-as 2
neighbor 172.16.1.2 ebgp-multihop 2
neighbor 172.16.1.2 update-source Loopback1
neighbor 172.17.1.2 remote-as 2
neighbor 172.17.1.2 ebgp-multihop 2
neighbor 172.17.1.2 update-source Loopback2
no auto-summary
3825-1#sh run | i ip route
ip route 172.16.1.2 255.255.255.255 100.10.10.2
ip route 172.17.1.2 255.255.255.255 100.20.20.2
3825-1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
GigabitEthernet0/0 100.10.10.1 YES NVRAM up up
GigabitEthernet0/1 100.20.20.1 YES NVRAM up up
Loopback1 172.16.1.1 YES NVRAM up up
Loopback2 172.17.1.1 YES NVRAM up up
Loopback123 123.123.123.123 YES manual up up
R1 Configuration
1841-1#sh run | s router
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
redistribute connected
redistribute static
network 1.1.1.1 0.0.0.0 area 0
network 192.168.1.1 0.0.0.0 area 0
default-information originate always
router bgp 2
no synchronization
bgp log-neighbor-changes
redistribute ospf 1
neighbor 4.4.4.4 remote-as 2
neighbor 4.4.4.4 update-source Loopback1
neighbor 4.4.4.4 next-hop-self
neighbor 172.16.1.1 remote-as 1
neighbor 172.16.1.1 ebgp-multihop 2
neighbor 172.16.1.1 update-source Loopback0
neighbor 172.16.1.1 route-map local-pref in
no auto-summary
route-map local-pref permit 10
set local-preference 200
1841-1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 100.10.10.2 YES NVRAM up up
FastEthernet0/1 192.168.1.1 YES NVRAM up up
Loopback0 172.16.1.2 YES NVRAM up up
Loopback1 1.1.1.1 YES NVRAM up up
1841-1#
R2 configuration
2651-1#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 192.168.2.2 YES NVRAM up up
FastEthernet0/1 192.168.1.2 YES NVRAM up up
Loopback2 2.2.2.2 YES NVRAM up up
2651-1#sh run | s router
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
network 192.168.1.2 0.0.0.0 area 0
network 192.168.2.2 0.0.0.0 area 0
R3 Configuration
2651-2#sh run | s router
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 192.168.2.3 0.0.0.0 area 0
network 192.168.3.3 0.0.0.0 area 0
2651-2#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 192.168.2.3 YES NVRAM up up
FastEthernet0/1 192.168.3.3 YES NVRAM up up
Loopback3 3.3.3.3 YES NVRAM up up
R4 Configuration
1841-2#sh run | s router
router ospf 1
router-id 4.4.4.4
log-adjacency-changes
redistribute connected
redistribute static
network 4.4.4.4 0.0.0.0 area 0
network 192.168.3.4 0.0.0.0 area 0
default-information originate always metric 10
router bgp 2
no synchronization
bgp log-neighbor-changes
redistribute ospf 1
neighbor 1.1.1.1 remote-as 2
neighbor 1.1.1.1 update-source Loopback4
neighbor 1.1.1.1 next-hop-self
neighbor 172.17.1.1 remote-as 1
neighbor 172.17.1.1 ebgp-multihop 2
neighbor 172.17.1.1 update-source Loopback1
no auto-summary
1841-2#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 192.168.3.4 YES NVRAM up up
FastEthernet0/1 100.20.20.2 YES NVRAM up up
Loopback1 172.17.1.2 YES NVRAM up up
Loopback4 4.4.4.4 YES NVRAM up up
cyruslab 