Configure OSPFv2 Single Area on Cisco Router (Point to Point – Serial Interface)

Configure OSPFv2 Single Area on Cisco Router (Point to Point – Serial Interface)

When working with Cisco routers in networking, configuring OSPFv2 (Open Shortest Path First version 2) in a single area is a common and important skill. This tutorial walks you through setting up OSPFv2 for a simple point-to-point serial interface topology.

Dynamic Routing – OSPFv2 (IPv4)

  1. Configure OSPFv2 Single Area on Cisco Router (Multiaccess – Ethernet Interface)
  2. Configure OSPFv2 Single Area on Cisco Router (Point to Point – Serial Interface)

Topology Overview

OSPFv2 Single Area on Cisco Router (Point to Point – Serial Interface) Topology
OSPFv2 Single Area on Cisco Router (Point to Point – Serial Interface) Topology

The topology consists of two routers (R1 and R2) connected via a serial interface (S0/1/0 on R1 and S0/1/1 on R2). Each router also has two Ethernet networks connecting to PCs:

  • Router R1:
    • Ethernet Network 1: 192.168.10.0/24
    • Ethernet Network 2: 192.168.20.0/24
    • Serial Network: 192.168.30.0/30
  • Router R2:
    • Ethernet Network 1: 192.168.40.0/24
    • Ethernet Network 2: 192.168.50.0/24
    • Serial Network: 192.168.30.0/30

The PCs in each network are assigned static IP addresses for communication.

Objective

The goal is to configure OSPFv2 in a single area (area 0) so that all networks connected to the routers can communicate with one another.

Configuration Steps

Step 1: Configure Router R1

  1. Assign Hostname: 
    Router>enable
Router#configure terminal
Router(config)#hostname R1
  2. Configure Gigabit Ethernet Interfaces: 
    R1(config)#interface gigabitEthernet 0/0/1
R1(config-if)#no shutdown
R1(config-if)#ip address 192.168.10.1 255.255.255.0
R1(config-if)#exit

    R1(config)#interface gigabitEthernet 0/0/2
R1(config-if)#no shutdown
R1(config-if)#ip address 192.168.20.1 255.255.255.0
R1(config-if)#exit
  3. Configure Serial Interface: 
    R1(config)#interface serial 0/1/0
R1(config-if)#no shutdown
R1(config-if)#ip address 192.168.30.1 255.255.255.252
R1(config-if)#exit
  4. Enable OSPFv2 and Advertise Networks: 
    R1(config)#router ospf 1
R1(config-router)#network 192.168.10.0 0.0.0.255 area 0
R1(config-router)#network 192.168.20.0 0.0.0.255 area 0
R1(config-router)#network 192.168.30.0 0.0.0.255 area 0
R1(config-router)#exit

Step 2: Configure Router R2

  1. Assign Hostname: 
    Router>enable
Router#configure terminal
Router(config)#hostname R2
  2. Configure Gigabit Ethernet Interfaces: 
    R2(config)#interface gigabitEthernet 0/0/1
R2(config-if)#no shutdown
R2(config-if)#ip address 192.168.40.1 255.255.255.0
R2(config-if)#exit

    R2(config)#interface gigabitEthernet 0/0/2
R2(config-if)#no shutdown
R2(config-if)#ip address 192.168.50.1 255.255.255.0
R2(config-if)#exit
  3. Configure Serial Interface: 
    R2(config)#interface serial 0/1/1
R2(config-if)#no shutdown
R2(config-if)#ip address 192.168.30.2 255.255.255.252
R2(config-if)#exit
  4. Enable OSPFv2 and Advertise Networks: 
    R2(config)#router ospf 1
R2(config-router)#network 192.168.30.0 0.0.0.255 area 0
R2(config-router)#network 192.168.40.0 0.0.0.255 area 0
R2(config-router)#network 192.168.50.0 0.0.0.255 area 0
R2(config-router)#exit

Verification

After completing the configurations, verify the OSPF neighbor relationship and routing table.

  1. Check OSPF Neighbors: On both routers, use the following command: 
    R1#show ip ospf neighbor
  2. Verify the Routing Table: Check the routes learned via OSPF: 
    R1#show ip route
  3. Test Connectivity: Use the ping command from any PC to verify connectivity with devices in other networks.

Conclusion

By following this tutorial, you have successfully configured OSPFv2 in a single area for a Cisco router network with a point-to-point serial interface. This setup ensures dynamic routing and seamless communication between all connected networks.