What is the correct sequence of steps a router takes when forwarding a packet destined for another network?

• A. De-encapsulates the Layer 2 frame header and trailer to expose the Layer 3 packet; examines the destination IP address to find the best path in the routing table; if a path is found, encapsulates the Layer 3 packet into a new Layer 2 frame and forwards the frame out the exit interface.
• B. Examines the IP header before de-encapsulating the Layer 2 frame, then forwards without encapsulation.
• C. Encapsulates the Layer 3 packet into a Layer 2 frame and broadcasts it on all interfaces.
• D. Drops the packet if the destination is not directly connected.

Answer: (A)

When forwarding a packet to another network, the router first removes the Layer 2 frame header and trailer to expose the Layer 3 IP packet. It then examines the destination IP address and consults its routing table to determine the best path and the next hop. If a route is found, the router encapsulates the IP packet into a new Layer 2 frame addressed to the next-hop's MAC address on the chosen exit interface and forwards it out that interface. If no route exists, the router will typically drop the packet (often sending an ICMP destination-unreachable message). The other options skip the necessary re-encapsulation, broadcast to all interfaces, or assume the destination is directly connected, which isn’t how routing forwards packets to remote networks.