I was assigned to capture the packets which are used in CSMA/CD protocol over the local network.

I have googled around for more than a day but haven't found any solution or related work that negotiate how to set up the environment.

I have tried to simulate by using 3 computers connected to the same router by wired (Airport Extreme) I called them station A, B, and C.

I install and used the wireshark on these stations to capture the packets.

I let the station A and B ping to C for about 2 minutes after that I stopped and saved the traces from all stations.

I have analyzed the packet by using the error, retransmission, and broadcast filter.

But, I haven't seen any collisions.

Did I do something wrong ? Is there any other suggestion for setting up the environment to simulate the CSMA/CD ? 

Thank you.

PS. Sorry for my english.