Why is a default route important in a routing table?

• A. It provides a path for traffic with no longer-prefix matches to exit the local network via a next-hop gateway
• B. It blocks any traffic that has no matching route
• C. It routes traffic only to a specific subnet
• D. It duplicates routing information to all routers

Answer: (A)

A default route provides a catch-all path in the routing table for destinations that don’t match any more specific entries. Routers pick routes using the longest-prefix match, so when no existing route covers a destination, the default route is used to forward the packet toward a designated next-hop gateway or exit interface. This lets devices reach networks beyond the local subnet, such as the Internet, by handing off unknown traffic to a router that can forward it onward. Without a default route, packets with destinations not in the local routing table would be dropped.

The other ideas don’t fit because a default route isn’t about blocking traffic, routing only to a single subnet, or duplicating routing information to all routers. It’s simply a fallback path to ensure reachability beyond the local network.