OSPF Multi Area Virtual Link

CCNP Route (300-101) Lab: Configuring OSPF Multi Area Virtual Link

Scenario: Virtual link is used when connecting the backbone (area 0) to non backbone area. Loopback IP address of R1 should be able to ping loopback IP address of R4, vice versa. R4 is not directly connected to area 0. Hence, a virtual link must be established between R3 and R4 in order for R1 and R4 to ping each other.

Syntax: area <number> virtual-link <neighbor router ID>

Configuration:

R1
en
conf t
host R1
int s0/0
ip add 200.1.1.1 255.255.255.252
no shut
int lo0
ip add 10.1.1.1 255.255.255.0
no shut
exit
router ospf 1
router-id 10.1.1.1
network 10.1.1.0 0.0.0.255 area 1
network 200.1.1.0 0.0.0.3 area 0
exit

R2
en
conf t
host R2
int s0/0
ip add 200.1.1.2 255.255.255.252
no shut
int s0/1
ip add 200.1.1.5 255.255.255.252
no shut
exit
router ospf 1
router-id 200.1.1.5
network 200.1.1.0 0.0.0.3 area 0
network 200.1.1.4 0.0.0.3 area 0
exit

R3
en
conf t
host R3
int s0/1
ip add 200.1.1.6 255.255.255.252
no shut
int fa0/0
ip add 100.1.1.1 255.255.255.0
no shut
int lo0
ip add 192.168.1.1 255.255.255.0
no shut
exit
router ospf 1
router-id 192.168.1.1
network 100.1.1.0 0.0.0.255 area 2
network 192.168.1.0 0.0.0.255 area 2
network 200.1.1.4 0.0.0.3 area 0
area 2 virtual-link 20.1.1.1
exit

R4
en
conf t
host R4
int fa0/0
ip add 100.1.1.2 255.255.255.0
no shut
int lo0
ip add 20.1.1.1 255.255.255.0
no shut
exit
router ospf 1
router-id 20.1.1.1
network 20.1.1.0 0.0.0.255 area 3
network 100.1.1.0 0.0.0.255 area 2
area 2 virtual-link 192.168.1.1
exit

Note: You must have basic knowledge of CCNA or equivalent as this is the prerequisite for CCNP. This lab is using GNS3 with C3745 router.