Question

Sender send a packet to Receiver. Explain the address change process (IP and MAC) in the packet. LAN 1 Sender A/10 To another network F/20 T/99 2010 AP Data 2010 AP Data Router 1 33 99 AP Data Physical addresses changed LAN 2 9566 A P Data 95 66 AP Data Router 2 33 99 AP Data P/95 N/33 Z/66 Physical addresses changed To another network Receiver LAN 3

Answer 1

ip address : used for source to destination data transfer , so it won't change while data pass through computer nodes/routers/switch etc.

MAC address / phisical address: change when data pass through nodes., physical address used for node to node data communication.

note:- routers have more than 1 interfaces . so more than 1 physical address

here the data transmision is as follows.

sender ------> Router 1 ---> Router 2 ---- > Receiver

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data communication explained below

1) sender ------> Router 1

      sender send data to interface F of Router 1 .

      sender MAC address : 10 .

      Router 1 MAC address : 20 ( interface F)

      

2) Router 1 ----> Router 2

       Interface F of Router1 Receive The Data, it check the IP address, it transmit data to interface T

       Through interface T of Router 1, send data to interface N of Router 2 ( MAC address changed )

       Router 1 MAC : 99 ( interface T)

       Router 2 MAC : 33 ( interface N)

3) Router 2--------> Receiver

        Interface N of Router2 Receive The Data, it check the IP address, it transmit data to interface Z.

        Through interface Z of Router 2, send data to Receiver. ( MAC address changed )

        Router 2 MAC : 66 ( interface N)

        Receiver MAC :95 ( interface P )

        Interface P of Receiver accept The Data, because it check the IP address, It understand this IP belongs to  

      itself. and handover data to upper layers.

        

      ********** MAC address changed 2 times