Which action does the router take as it forwards a packet through the network?
Click on the arrows to vote for the correct answerA. B. C. D.
When a router receives a packet from a source device, it must forward the packet to the appropriate destination. As it forwards the packet through the network, the router takes the following actions:
C. The router replaces the original source and destination MAC addresses with the sending router MAC address as the source and neighbor MAC address as the destination.
The process of replacing the original MAC addresses with the sending router MAC address as the source and the neighbor MAC address as the destination is known as MAC address substitution. This is done to ensure that the packet is forwarded to the correct destination.
B. The router encapsulates the source and destination IP addresses with the sending router IP address as the source and the neighbor IP address as the destination.
Once the MAC addresses have been replaced, the router then encapsulates the packet with a new IP header. The new header includes the sending router's IP address as the source and the neighbor's IP address as the destination. This is known as IP address encapsulation.
A. The router encapsulates the original packet and then includes a tag that identifies the source router MAC address and transmits it transparently to the destination.
After the IP header has been added, the packet is encapsulated again, this time with a layer 2 header that includes the new MAC addresses. This process is known as MAC encapsulation. The router then transmits the packet to the next hop along the path to the destination.
D. The router replaces the source and destination labels with the sending router interface label as a source and the next hop router label as a destination.
Label switching is used in MPLS networks to forward packets between routers. In this process, the router replaces the source and destination labels with the sending router interface label as the source and the next hop router label as the destination. The packet is then forwarded to the next hop router based on its label.
In summary, the router takes the following actions when forwarding a packet through the network: MAC address substitution, IP address encapsulation, MAC encapsulation, and label switching (in MPLS networks).