World of Computer Networking Your CCNA start - End-to-End Internet Protocol (IP) Packet Transmission - Part 2

The video tutorial explains the process of packet forwarding in a network. It begins with the router receiving a packet at its Gigabit 0/0 interface, performing decapsulation, and checking the routing table to determine the next hop. The router sends an ARP request to resolve the MAC address of the destination host. After receiving the MAC address, the router decrements the TTL, updates the header checksum, and encapsulates the packet with a new Ethernet header. Finally, the router transmits the Ethernet frame through the appropriate interface.

What does the router do when it receives a packet with a destination IP address that doesn't match any of its own addresses?

• It stores the packet for later processing.

• It discards the packet.

• It forwards the packet to the next hop.

• It sends the packet back to the sender.

How does the router determine if a route is a match in the routing table?

• By checking if the destination IP is in the same subnet as the router.

• By applying the subnet mask to the destination IP and comparing it with the routing table prefix.

• By comparing the destination IP address with the router's IP address.

• By looking for an exact match of the destination IP in the routing table.

What action does the router take if it does not know the MAC address of the destination host?

• It sends a unicast message to the host.

• It drops the packet.

• It sends a broadcast ARP request to all devices on the network.

• It forwards the packet without a MAC address.

What happens to the TTL field of the packet when it is processed by the router?

• It is reset to zero.

• It is incremented by one.

• It is decremented by one.

• It remains unchanged.

Why does the router need to recalculate the header checksum?

• Because the packet size has increased.

• Because the source IP address has changed.

• Because the TTL field has been modified.

• Because the destination IP address has changed.

What is the purpose of adding a new Ethernet header to the packet?

• To update the source and destination IP addresses.

• To include the source and destination MAC addresses.

• To change the IP version.

• To encrypt the packet data.

Which interface does the router use to send the packet after processing?

• Gigabit 1/2

• Gigabit 1/0

• Gigabit 0/1

• Gigabit 0/0