Sniff Ethernet with a throwing star

[Michael Ossmann] came up with a nifty little device that arranges RJ45 plugs into a plus shape for the intent of sniffing Ethernet packets, and named it the “Throwing Star LAN Tap”. While the original design worked fine it does suffer some limitations such as being limited to 10/100 base networks, and one way only. This new version of the “Throwing Star LAN Tap” fixes those and adds some much needed convenience.

Gone are the male plugs, which requires couplers and are prone to break, and fiddly splices in favor of a throwing star shaped pcb, and female sockets. 1000 base networks are supported, but due to the workings of 1000 base and wanting to keep the device passive, capacitors are added to filter out the signal and force the network to drop down to 100 base. Sure, it may be an ugly hack, but it’s an ugly hack that fits in your pocket.