Today I wired up a passive network TAP. I followed the TAP wiring diagram found at this website. I also took into account some of the comments found on other sites that explain how to make a passive TAP. So, unlike some of the photos found online, I worked to maintain the twist in the wires to keep the interference down. I used CAT5e rated ports and wire, a face plate and small matching white box to enclose the back. All parts found at Home Depot. Cost was about $18 - $20 bucks and maybe 20 – 30 minutes to wire and assemble.
I’ll test it out at work tomorrow where I have a laptop setup with Wireshark running full time. Currently I’m using port mirroring but this should give me a more complete picture with all the packets that the switch might filter out. It will also reduce the load on the switch, not having to mirror all that data to another port. This will also free up that port for other use. I have a spare desktop computer with 2 NIC’s so I can get both sides of the traffic if the initial test is good.
