I have a passive network tap that I have put between two hosts. The cabling scheme of the tap looks like this:
The tap is connecting only two pins (one twisted pair) to each of the two network cards that are used for traffic monitoring. I have the problem that one network card (which is built in) works fine under that setup (the link light is on and it receives/monitor traffic), but the other network card, which is a USB network card does not receive anything and the link light is off.
Promiscuous mode is ON on both cards. I get the same results after switching the cables between the network cards. The USB network card can sniff traffic if I connect to a standard host (with all pins connected). The device the USB NIC is connected to is a Raspberry pi, so that's why I have to use a USB NIC as the second NIC.
Is there any way I can make the USB NIC receive traffic if only two pins are connected?