Aruba Y Cable Pin layout

If you work with Aruba Wireless Access Point, then a Aruba Y cable could be a good troubleshooting tool for you. One end of the Y cable looks like regular female RS232/DB9 port. The other end looks like two Ethernet cable with RJ45 connectors. You will need to plug one RJ45 connector to an AP, the other RJ45 connector to a POE switch port, and the serial connector to your PC's serial port. From a Putty session, you can see all the traffic between the AP and your network.

Here is a diagram of the Y cable's pin layout if you want to make one yourself. You will need a short Ethernet patch cord (568B at both ends) and a female DB9 adapter kit.

Carefully cut open the sleeve of the patch cord in the middle, cut open the blue, white/blue, brown, and white/brown wires, strip off the plastic cover on those wires, and wire them to pin 2, 3, & 5 from inside of the DB9 connector as shown at the bottom of the diagram - white/blue and brown wires are both connected to pin 5. The White/Orange, Orange, White/Green and Green should be untouched ans still connected to both end of the RJ45 Connectors. I erased the other 4 wires at the network end of the connector in the diagram. But in reality, they are still there, just being cut.

In one case I need to use the Y cable is one AP would not show up in master controller after been configured as a mash point. Using the cable, I was able to see the boot process and the behavior of the AP after the boot process. That provided enough information to google and find solution, which is break the boot process by press Enter key in a 2-5 seconds time window, then enter "purge" and "save" command and reboot the AP.