Your software may not support Open Shortest Path First (OSPF).
If you are using a Cisco 1600 Series Router, you need a Plus image to run OSPF.
Determine if you are running the appropriate Cisco IOS Software feature set to configure OSPF by using the Cisco Feature Navigator.
For information on Cisco Feature Navigator II, refer to Cisco IOS Software: Cisco Feature Navigator II.
Receiving "ospf unknown protocol" error message