What is the role of the Gateway of Last Resort when there is no route to the destination?

• A. It is used to forward packets when no specific route exists
• B. It is the primary route for directly connected networks
• C. It is used only for multicast routing
• D. It is an alternative to a firewall

Answer: (A)

When a router doesn’t have a more specific route for a destination, it uses a gateway of last resort as the default path to forward the packet. This default route, often shown as 0.0.0.0/0 (IPv4) or ::/0 (IPv6), points to a next-hop or exit point toward the wider network or Internet. Without it, the router would have to drop packets with unknown destinations, but with it, unknown traffic can still be sent toward a configured gateway that can handle it.

This role is not about routes to directly connected networks, which have explicit entries for the local interfaces. It’s also not specific to multicast routing, which relies on different protocols and mechanisms. And it’s not an alternative to a firewall—the gateway of last resort simply forwards traffic; firewall functionality governs what traffic is allowed or blocked.