GNS3 configuration:


Create this lab in GNS3 with the following configuration, after these configurations you can start real lab configuration as you need to complete in the exam.

R1 Configuration:
R1(config)#ipv6 unicast-routing
R1(config)#interface Loopback1
R1(config-if)# ipv6 address FEC0:11::1/64
R1(config-if)#ipv6 ospf 1 area 0
R1(config-if)#EXIT
R1(config-if)#interface FastEthernet1/0
R1(config-if)#ipv6 address FEC0:1::1/64
R1(config-if)#no shut
R1(config-if)#ipv6 ospf 1 area 0
R1(config-if)#exit
R1(config)#ipv6 router ospf 1
R1(config-rtr)#router-id 1.1.1.1


R2 Configuration:

 
R2(config)#ipv6 unicast-routing
R2(config)#int loopback 1
R2(config-if)#ipv6 address fec0:22::2/64
R2(config-if)#ipv6 ospf 1 area 0
R2(config-if)#EXIT
R2(config-if)#interface FastEthernet1/0
R2(config-if)#ipv6 address FEC0:1::2/64
R2(config-if)#no shut
R2(config-if)#ipv6 ospf 1 area 0
R2(config-if)#exit
R2(config-if)#interface serial2/0
R2(config-if)#ipv6 address FEC0:2::1/64
R2(config-if)#no shut
R2(config-if)#ipv6 ospf 1 area 11
R2(config-if)#EXIT
R2(config)#ipv6 router ospf 1
R2(config-rtr)#router-id 2.2.2.2

R3 Configuration: 


R3(config)#ipv6 unicast-routing
R3(config)#int loopback 1
R3(config-if)#ipv6 address fec0:33::3/64
R3(config-if)#ipv6 ospf 1 area 11
R3(config-if)#EXIT
R3(config-if)#interface FastEthernet1/0
R3(config-if)#ipv6 address FEC0:3::1/64
R3(config-if)#no shut
R3(config-if)#ipv6 ospf 1 area 54
R3(config-if)#exit
R3(config-if)#interface serial2/0
R3(config-if)#ipv6 address FEC0:2::2/64
R3(config-if)#no shut
R3(config-if)#ipv6 ospf 1 area 11
R3(config-if)#EXIT
R3(config)#ipv6 router ospf 1
R3(config-rtr)#router-id 3.3.3.3


Follow virtual-link configuration are wrong I have added these because in real exam you will find such wrong configuration and you need to remove these and need to configure R2 & R3 for virtual-link. Also in exam configuration, I shall removes this area 54 virtual-link 4.4.4.4 command from R3 so that all routers can communicate with each other.
R3(config-rtr)# area 54 virtual-link 4.4.4.4 

R4 Configuration: 


R4(config)#ipv6 unicast-routing
R4(config)#int loopback 1
R4(config-if)#ipv6 address fec0:44::4/64
R4(config-if)#ipv6 ospf 1 area 54
R4(config-if)#EXIT
R4(config-if)#interface FastEthernet1/0
R4(config-if)#ipv6 address FEC0:3::2/64
R4(config-if)#no shut
R4(config-if)#ipv6 ospf 1 area 54
R4(config-if)#exit
R4(config)#ipv6 router ospf 1
R4(config-rtr)#router-id 4.4.4.4


Configuration required in Exam:


In this lab, you need to configure a virtual link for area 11 so that end to end communication can be possible.
Step-1:
Show Run on R1, R2, and R3, and check the virtual links commands, if you found any of router please remove these first. Also, note the router-ids and OSPF process ID. In real exam IP addresses, OSPF process ids and area ids maybe change, so you need to figure out the exact values by using show run.
For example, in R3 configuration you found area 54 virtual-link 4.4.4.4 which is unnecessary. 



So please remove this.  You need to make the virtual link on R2 & R3. We create virtual links when some OSPF area is not physically connected with backbone area (Area 0). The area through which you configure the virtual link is known as a transit area. Routers R2 and R3 are belonging to transit area that way need to add commands on these routers.


R4#configure terminal
R4(config)#ipv6 router OSPF 1
R4(config-rtr)#no area 54 virtual-link 3.3.3.3
Step-2:
Complete the virtual links configurations on R2 & R3.

R3>enable
R3#configure terminal
R3(config)#ipv6 router OSPF 1
R3(config-rtr)#no area 54 virtual-link 4.4.4.4 
R3(config-rtr)#area 11 virtual-link 2.2.2.2

R2>enable
R2#configure terminal
R2(config)#ipv6 router ospf 1
R2(config-rtr)#area 11 virtual-link 3.3.3.3
R4>enableR4#show running-config
You will see a wrongly configured virtual-link command. To get full mark we have to disable this command:
Verification:
After configuration use command “Show IPv6 route” on R1, if you found the R4 route in routing table its mean you have done this lab successfully. And ping from R1 to R4 should be successful.