What is a routing protocol?

• A. Protocols responsible for addressing and packet sequencing
• B. Protocols responsible for path determination and packet switching
• C. Protocols used for message authentication
• D. Protocols that control access rights

Answer: (B)

Routing protocols decide how data should travel across a network by figuring out the best path from source to destination and guiding routers to forward packets along that path. They build and update routing tables, exchange topology information, and use metrics like distance, delay, or bandwidth to choose routes. The actual movement of each packet—how it is sent from one router to the next and eventually to its destination—is carried out based on those routing decisions.

This is why the option describing path determination and packet forwarding (switching) is the best fit. The other ideas focus on security (authentication) or access control, which are not what routing protocols handle, and they don’t capture the network-layer function of choosing routes and enabling packets to be forwarded along those routes.