Question

Please see the problem! Not asking C’s!!!!!

As laptop A, B, C and Router each attach to the same broadcast LAN (through their adapters). If A sends datagrams to Router with each encapsulating frame addressed to the MAC address of Router, will B’s adapter process these frames? If so, will B’s adapter pass the IP datagrams in these frames to the network layer B? What if A sends frames with the MAC broadcast address?

Answer 1

In case of any doubt, please comment and I will be there to discuss :). Its a nice question and i think an extension to already available problem. So please look at the solution and if you find it helpful, do up-vote, it means a lot to me.

Answer. B's adapter will process the frames but B's adapter will not pass the IP datagrams in these frames to network layer B. It is because of the fact that MAC address used if of router. B will get the frame and check the address but since it is not B's Physical address it won't pass these datagrams.

Now, if A sends frames with the MAC broadcast address,then B’s adapter will both process the frames and pass the datagrams up the protocol stack (since we know that broadcasting is done to get packet to each connected device. )

There's a similar question which forward packet to C. As far a I think, the problem is quite similar due to the MAC addresses which are unique for each device and also MAC addresses has nothing to do with router table as router is layer 3 device while MAC addresses comes in layer 2. (As one can think about the case in which router contains addresses). If we use IP addresses for any type of comm. in which router is involved, scenario will be different.