Prerequisites: CCNP level skills.
Topology
Pic. 1 – OSPF Topology.
Task 1
Configure OSPF in area 0, area 1 and area 2 as per pic. 1.
Task 2
Configure OSPF in area 3 as per pic. 1. Make sure that all routers in area 3 have full reachability to the rest of the network.
Lab Solution
Task 1
Configure OSPF in area 0, area 1 and area 2 as per pic. 1.
R1 OSPF Configuration:
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 10.1.12.1 0.0.0.0 area 0
network 10.1.13.1 0.0.0.0 area 1
network 172.16.101.1 0.0.0.0 area 0
router-id 1.1.1.1
log-adjacency-changes
network 10.1.12.1 0.0.0.0 area 0
network 10.1.13.1 0.0.0.0 area 1
network 172.16.101.1 0.0.0.0 area 0
!
R2 OSPF Configuration:
!
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
network 10.1.12.2 0.0.0.0 area 0
network 10.1.24.2 0.0.0.0 area 2
network 172.16.102.2 0.0.0.0 area 0
!
router-id 2.2.2.2
log-adjacency-changes
network 10.1.12.2 0.0.0.0 area 0
network 10.1.24.2 0.0.0.0 area 2
network 172.16.102.2 0.0.0.0 area 0
!
R3 OSPF Configuration:
!
router ospf 1
router-id 3.3.3.3
log-adjacency-changes
network 10.1.13.3 0.0.0.0 area 1
network 10.1.35.3 0.0.0.0 area 1
network 172.16.103.3 0.0.0.0 area 1
!
router-id 3.3.3.3
log-adjacency-changes
network 10.1.13.3 0.0.0.0 area 1
network 10.1.35.3 0.0.0.0 area 1
network 172.16.103.3 0.0.0.0 area 1
!
R4 OSPF Configuration:
!
router ospf 1
router-id 4.4.4.4
log-adjacency-changes
network 10.1.24.4 0.0.0.0 area 2
network 172.16.104.4 0.0.0.0 area 2
!
router-id 4.4.4.4
log-adjacency-changes
network 10.1.24.4 0.0.0.0 area 2
network 172.16.104.4 0.0.0.0 area 2
!
R5 OSPF Configuration:
!
router ospf 1
router-id 5.5.5.5
log-adjacency-changes
network 10.1.35.5 0.0.0.0 area 1
network 172.16.105.5 0.0.0.0 area 1
!
router-id 5.5.5.5
log-adjacency-changes
network 10.1.35.5 0.0.0.0 area 1
network 172.16.105.5 0.0.0.0 area 1
!
Task 2
Configure OSPF in area 3 as per pic. 1. Make sure that all routers in area 3 have full reachability to the rest of the network.
Note!
Area 3 does not have a direct connectivity to the backbone area (area 0). In order for area 3 routers to receive all the LSAs and get the reachability to the rest of the domain, a virtual link between R2 and R4 is required. The transit area (area 2) must be a normal area (not a stub one) for the virtual link to work.
R2 OSPF Configuration:
!
router ospf 1
router-id 2.2.2.2
log-adjacency-changes
network 10.1.12.2 0.0.0.0 area 0
network 10.1.24.2 0.0.0.0 area 2
network 172.16.102.2 0.0.0.0 area 0
router-id 2.2.2.2
log-adjacency-changes
network 10.1.12.2 0.0.0.0 area 0
network 10.1.24.2 0.0.0.0 area 2
network 172.16.102.2 0.0.0.0 area 0
area 2 virtual-link 4.4.4.4
!
R4 OSPF Configuration:
!
router ospf 1
router-id 4.4.4.4
log-adjacency-changes
network 10.1.24.4 0.0.0.0 area 2
network 172.16.104.4 0.0.0.0 area 2
router-id 4.4.4.4
log-adjacency-changes
network 10.1.24.4 0.0.0.0 area 2
network 172.16.104.4 0.0.0.0 area 2
network 10.1.46.4 0.0.0.0 area 3
area 2 virtual-link 2.2.2.2
!
!
R6 OSPF Configuration:
!
router ospf 1
router-id 6.6.6.6
log-adjacency-changes
network 10.1.46.6 0.0.0.0 area 3
network 172.16.106.6 0.0.0.0 area 3
router-id 6.6.6.6
log-adjacency-changes
network 10.1.46.6 0.0.0.0 area 3
network 172.16.106.6 0.0.0.0 area 3
!
Verification:
Pic. 2 – R2 Virtual Link.
Pic. 3 – R2 OSPF Neighbor Adjacency.
Pic. 4 – R6’s Routing Table.
