What is the purpose of routing protocols like OSPF or RIP?

• A. To troubleshoot connectivity issues on a host
• B. To dynamically exchange routing information and compute best paths between routers
• C. To assign IP addresses automatically
• D. To provide firewall rules for traffic filtering

Answer: (B)

Routing protocols enable routers to dynamically exchange routing information and determine the best paths between networks. They share knowledge about which networks are reachable, the cost or metric to reach them, and how to reach them efficiently, so the network can adapt when links fail or change.

OSPF does this with a link-state approach: each router builds a complete map of the network and runs a shortest-path algorithm to compute the best route to every destination, updating quickly as topology changes. RIP uses a simpler distance-vector approach, sharing hop counts with neighbors and periodically updating, which works but converges more slowly and limits the maximum number of hops.

This dynamic exchange and automatic path calculation is what routing protocols are for. They aren’t primarily about troubleshooting a host, automatically assigning IP addresses, or configuring firewall rules.