OSPF Configuration Basics

On a Cisco router Open Shortest Path First(OSPF) can be configured. This can be done with only a few commands on the router. The commands that can be used to configure OSPF on a Cisco router along with their syntax can be found below.

1. (config)#router ospf [INSTANCE NUMER] - where the instance number is usually 1

2. (config-router)#network [NETWORK ADDRESS] [WILDCARD MASK] area 0 - where the Netowork Address and Wildcard Mask are defined approriately.

KEEP IN MIND:

• Routers in the same area must be assigned the same area number.
• The second OSPF command must be performed for each network that the router is a direct part of.

Lab Configuration

For the labs, after configuring interfaces, I configured each router in the area to use OSPF. The commands I used for each router can be found below. THe commands shown contain addresses used in the packet tracer lab.

West Router

The west router is connected to the 10.26.40.0/24 and 10.26.1.32/30 networks. The commands I used for OSPF configuration on the West Router are shown below:

Zachary-West-Router4(config)#router ospf 1
Zachary-West-Router4(config-router)#network 10.26.40.0 0.0.0.255 area 0
Zachary-West-Router4(config-router)#network 10.26.1.32 0.0.0.3 area 0

East Router

The east router is connected to the 10.26.20.0/24 and 10.26.1.20/30 networks. The commands I used for OSPF configuration on the east Router are shown below:

Zachary-East-Router2(config)#router ospf 1
Zachary-East-Router2(config-router)#network 10.26.20.0 0.0.0.255 area 0
Zachary-East-Router2(config-router)#network 10.26.1.20 0.0.0.3 area 0

Data Center Router

The data center router is connected to the 10.26.1.0/29, 10.26.1.20/30, and 10.26.1.32/30 networks. The commands I used for OSPF configuration on the data center router are shown below:

Zachary-DataCenter-Router3(config)#router ospf 1
Zachary-DataCenter-Router3(config-router)#network 10.26.1.0 0.0.0.7 area 0
Zachary-DataCenter-Router3(config-router)#network 10.26.1.20 0.0.0.3 area 0
Zachary-DataCenter-Router3(config-router)#network 10.26.1.32 0.0.0.3 area 0

Border Router

The data center router is connected to the 10.26.1.0/29 network. The commands I used for OSPF configuration on the data center router are shown below:

Zachary-Border-Router1(config)#router ospf 1
Zachary-Border-Router1(config-router)#network 10.26.1.0 0.0.0.7 area 0

After configuration of OSPF on each router, I was able to successfully ping between devices connected to the east and west routers. I was also able to use the sh ip route command to show the networks in the routing table.