At work, I have been tasked with monitoring the Ethernet frames between two modules that use automotive Ethernet (100BASE-T1). I am able to break this trunking connection and convert from automotive Ethernet to 10/100 Mbps Ethernet ports. However, we do not have the hardware that configures an active tap, and can't get one in time because of the chip shortage.
I'm new to the field of networking, and I did try to learn at one point. I did buy a WS-2950-48-EI Cisco Catalyst Switch at one point, and I have been thinking about using that instead. What I want to set up is a Tap 'Breakout' mode (see here). But after I make the connections, I am not sure how to configure my four interfaces:
1) How do I re-connect the broken interface between the two modules (let's say they are Cisco switch ports A and B)? What to configure so that traffic from port B reaches port A, and vice versa?
2) Will my modules stop communicating when they see the Cisco switch's MAC address, which is not a MAC address that they want to communicate with?
3) How do I then mirror that traffic onto the mirroring ports C and D, which will connect to my laptop? Is SPAN involved in this?
But I will like to ask for some help-- I am very new to this and would appreciate any pointers and suggestions that you all may have.
