How Routers Handle Packets with Unknown Routes

B

When a router is unable to find a known route in the routing table, it performs the following steps to handle the packet:

1. The router examines the destination IP address of the packet to determine if it has a route in its routing table.
2. If the router does not have a route for the destination IP address, it considers the packet as unreachable.
3. If the router has a default gateway configured (also known as the gateway of last resort), it sends the packet to the default gateway. The default gateway is usually the next-hop router that forwards the packet to its final destination.
4. If the router does not have a default gateway configured, it drops the packet and generates an ICMP message to notify the sender that the destination is unreachable.

So, from the given options, the correct answer would be B. It sends the packet to the gateway of last resort.