Which routing table entry represents the default route to any destination?

Which routing table entry represents the default route to any destination?

• A. 0.0.0.0/0 via F0/0
• B. 10.0.0.0/8 via F0/0
• C. 192.168.0.0/16 via F0/1
• D. 0.0.0.0/0 via F0/1

Answer: (A)

The default route is the catch-all path for any destination, expressed as 0.0.0.0/0. This prefix matches every possible IPv4 address, so packets whose destinations aren’t covered by more specific routes will be sent using that entry. Therefore, an entry like 0.0.0.0/0 via F0/0 directs all unknown destinations to go out through interface F0/0, which is exactly how the router reaches “any destination.” The other routes point to specific networks—10.0.0.0/8 targets only addresses in the 10.x.x.x range, and 192.168.0.0/16 targets only 192.168.x.x—so they do not serve as the universal default. A second default route such as 0.0.0.0/0 via F0/1 could exist, but the defining feature of the default route is the 0.0.0.0/0 prefix itself.

The default route is the catch-all path for any destination, expressed as 0.0.0.0/0. This prefix matches every possible IPv4 address, so packets whose destinations aren’t covered by more specific routes will be sent using that entry. Therefore, an entry like 0.0.0.0/0 via F0/0 directs all unknown destinations to go out through interface F0/0, which is exactly how the router reaches “any destination.” The other routes point to specific networks—10.0.0.0/8 targets only addresses in the 10.x.x.x range, and 192.168.0.0/16 targets only 192.168.x.x—so they do not serve as the universal default. A second default route such as 0.0.0.0/0 via F0/1 could exist, but the defining feature of the default route is the 0.0.0.0/0 prefix itself.