This guide will show you how to create an ethernet monitoring tap. The design is based on the famous Throwing Star LAN Tap by Great Scott Gadgets [http://greatscottgadgets.com/throwingstar/]. It allows you to monitor the flow of ethernet data between two points.
- Small Protoboard
- 4x RJ45 Ethernet Sockets
- 2x 220pF Capacitor
- Different colored wires. Thinner the better.
- Soldering iron
- Helping hands stand
- Mini hacksaw blade
- Wire cutters/strippers
Step 1. Cut the protoboard to size.
Step 2. Bend the second row of pins on the ethernet sockets so they're aligned with the top ones. Then insert all the components into the board.
Step 3. Solder the sockets and capacitors into place.
Step 4. Cut, strip and tin the little wires. The colors don't really matter, it will just help keep track of where everything is going.
Step 5. Refer to the circuit diagram, and solder the wires to the correct pins. This is pretty fiddly work, so take your time. As you go along, make sure all connections are solid, and no wires are damaged.
Step 6. Test the tap and then add something to cover the exposed wires. I used another piece of protoboard.
Finished. The grey ethernet sockets are for the traffic you wish to monitor and the black sockets are for the actual monitoring. Now you can hook it up and use your preferred network analysis tools to monitor the data.