Lab 24 - OSPF Virtual Link Example 1

Lab 24 - OSPF Virtual Link Example 1
Di Posting Oleh : Simple Learning
Kategori : Core Technologies OSPF Routing

Prerequisites: CCNP level skills.

Topology

Pic. 1 - OSPF Topology.

Icons designed by: Andrzej Szoblik - http://www.newo.pl

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

!

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
!

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
!

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
!

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
!

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

 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

 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

!

Verification:

Pic. 2 - R2 Virtual Link.

Pic. 3 - R2 OSPF Neighbor Adjacency.

Pic. 4 - R6's Routing Table.

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