In the following network diagram, you want to test the connectivity from PC-A to PC-B which are connected through a router in the middle. As part of this you pinged PC-B’s IP address from PC-A. Eventually this causes ICMP at PC-A to create an ICMP echo request packet which is to be delivered to PC-B. 

   

List and briefly describe the detail of IP routing and frame forwarding of the processes that deliver the above ICMP echo request packet to PC-B at the ICMP protocol of PC-B.

   

Address the following points in your explanation: 

   

1) How IP packet is created from ICMP packet at PC-A, i.e., describe the encapsulation of the ICMP payload into an IP packet (indicating values of relevant IP header fields). 

   

2) How IP at PC-A determines whether PC-B is a local or remote destination including any calculations performed. 

   

3) Once the location is determined in (2), a destination MAC address is required to prepare a frame. If PC-B is in remote, which device’s MAC address will be used for encapsulation of IP packet into a frame; mention the IP of that devices? Explain why this device. 

4) Once the frame is prepared and given to the physical layer of PC-A, list and briefly describe the remaining steps to deliver the frame to next device’s IP protocol, including decapsulation, routing decisions, and encapsulation, until the ICMP payload can be processed at PC-B.

 

Fa0/0 200.10.5.70/28 PC-A 200.10.5.68/28 Fa0/1 200.10.4.57/27 PC-B 200.10.4.59/27