HomeNetworkingCiscoImplementing OSPF Virtual Links on Cisco Routers

Implementing OSPF Virtual Links on Cisco Routers

Implementing OSPF Virtual Links on Cisco Routers

  • April 29, 2024
  • Posted by: Lyfey Technologies
  • Categories: Cisco, Networking
400 Comments

This article demonstrates how to configure OSPF Virtual links on Huawei devices: Implementing OSPF Virtual Links on Huawei Routers

This lab focuses on how to implement OSPF virtual links on Cisco Routers.

Configuration Steps

Step 1: Configure IP addresses on the interfaces on all the routers.

************************R1
enable
config terminal
!
hostname R1
!
interface FastEthernet0/0
 ip address 10.10.10.0 255.255.255.254
 no shutdown
!
interface FastEthernet0/1
 ip address 10.10.10.2 255.255.255.254
 no shutdown
!
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
************************R2
enable
config terminal
!
hostname R2
!
interface FastEthernet0/0
 ip address 10.10.10.3 255.255.255.254
 no shutdown
!
interface FastEthernet0/1
 ip address 10.10.10.4 255.255.255.254
 no shutdown
!
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
************************R3
enable
config terminal
!
hostname R3
!
interface FastEthernet0/0
 ip address 10.10.10.7 255.255.255.254
 no shutdown
!
interface FastEthernet0/1
 ip address 10.10.10.8 255.255.255.254
 no shutdown
!
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
************************R4
enable
config terminal
!
hostname R4
!
interface FastEthernet0/0
 ip address 10.10.10.9 255.255.255.254
 no shutdown
!
interface Loopback0
 ip address 4.4.4.4 255.255.255.255
!
************************R5
enable
config terminal
!
hostname R5
!
interface FastEthernet0/0
 ip address 10.10.10.1 255.255.255.254
 no shutdown
!
interface Loopback0
 ip address 5.5.5.5 255.255.255.255
!
************************R6
enable
config terminal
!
hostname R6
!
interface FastEthernet0/0
 ip address 10.10.10.5 255.255.255.254
 no shutdown
!
interface FastEthernet0/1
 ip address 10.10.10.6 255.255.255.254
 no shutdown
!
interface Loopback0
 ip address 6.6.6.6 255.255.255.255
!

Step 2: Configure OSPF on all the routers and advertise respective networks.

************************R1
!
router ospf 10
 router-id 1.1.1.1
 log-adjacency-changes
 network 1.1.1.1 0.0.0.0 area 0
 network 10.10.10.0 0.0.0.1 area 0
 network 10.10.10.2 0.0.0.1 area 0
!
************************R2
!
router ospf 10
 router-id 2.2.2.2
 log-adjacency-changes
 network 2.2.2.2 0.0.0.0 area 0
 network 10.10.10.4 0.0.0.1 area 1
 network 10.10.10.2 0.0.0.1 area 0
!
************************R3
!
router ospf 10
 router-id 3.3.3.3
 log-adjacency-changes
 network 3.3.3.3 0.0.0.0 area 1
 network 10.10.10.6 0.0.0.1 area 1
 network 10.10.10.8 0.0.0.1 area 2
!
************************R4
!
router ospf 10
 router-id 4.4.4.4
 log-adjacency-changes
 network 4.4.4.4 0.0.0.0 area 2
 network 10.10.10.8 0.0.0.1 area 2
!
************************R5
!
router ospf 10
 router-id 5.5.5.5
 log-adjacency-changes
 network 5.5.5.5 0.0.0.0 area 0
 network 10.10.10.0 0.0.0.1 area 0
!
************************R6
!
router ospf 10
 router-id 6.6.6.6 3.3.3.3
 log-adjacency-changes
 network 6.6.6.6 0.0.0.0 area 1
 network 10.10.10.6 0.0.0.1 area 1
 network 10.10.10.4 0.0.0.1 area 1
!

Step 3: Verify OSPF peer adjacencies and LSDB on all routers as follows.

Note: R1 and R6 dont have any information from Area 2 in their LSDBs. Similarly, R4 doe not have any details or LSAs from Area 1 and Area 0. We need to configure a virtual link for Area 2 to connect to Area 0 for it to be able to get LSAs from Area 1 and Area 0.

Step 4: Configure a virtual link for Area 2 on R2 and R3 as follows.

**********************R2
!
router ospf 10
 area 1 virtual-link 3.3.3.3
!
**********************R3
!
router ospf 10
 area 1 virtual-link 2.2.2.2
!

Step 5: Verify Virtual links status and recheck LSDBs on routers.

R1 now has LSAs from Area 2 in its LSDB. R4 also has LSA from Area 1 and Area 0 in its LSDB.

Thank you for reading our articles. Please check our website for more interesting content on networking.

Related Posts



400 Comments

Leave a Reply

This website uses cookies and asks your personal data to enhance your browsing experience.
Ok, I agree Privacy Policy

Privacy Policy