Which command enables a specific routing protocol process (e.g., OSPF) in configuration mode?

• A. enable routing protocol ospf
• B. show running-config
• C. router ospf <process-id>
• D. router rip <process-id>

Answer: (C)

To enable a specific routing protocol process in configuration mode, you enter that protocol’s router configuration submode using its process-id. In IOS, you go into global config mode and type router ospf . The process-id is a locally significant number that lets you run more than one OSPF instance on the same device if needed. Once you’re in that submode, you can configure networks, areas, and other OSPF settings for that particular process.

The other options don’t fit: a command like enable routing protocol ospf isn’t a valid IOS syntax; show running-config only displays current settings without enabling anything; and router rip is not how RIP is entered (RIP uses router rip without a process-id).