RSLinx Classic EtherNet to ControlNet

I have seen on my co-workers laptop that he is able to connect to multiple PLCs using his EtherNet port going into a PLC then thur the backplane of that PLC go out the ControlNet port and from there connect to every PLC on Control Net.

When I bring up RSWho I can see the PLC over Ethernet and see the controlNet Card but I dont see any other nodes on the control net Card.

What am I doing wrong?

What type of RSLinx driver are you using?
Make sure it's an EtherNet/IP type driver (and not Ethernet)!