1. Using a Web Service.

   1. Open http://wpad/wpad.dat.

   2. Figure the proxy out from the contents it returns.

2. Use the command netstat. This is a universal way and is especially helpful when http://wpad/wpad.dat is not available.

   1. Inspect the output of netstat -an | egrep "EST|Proto" ("EST" is short for "ESTABLISHED") in a Linux-like environment. You can use Cygwin if you are on Windows. Note that netstat comes with Windows not Cygwin. If you cannot use it in Cygwin, it is probably due to a misconfigured path environment variable. You can of course run the netstat -an command in the command prompt in Windows but you do not have a convenient command like grep.

   2. Go to a fresh site that you have not recently visited.

   3. Run the netstat -an | grep "EST" command again and look for the new connection. It might look like the following. In this example, your proxy's IP is 192.168.1.88 and it is listening on port 8080. A proxy server typcial listens to the 8080 port.

      TCP 192.168.1.1:1989 192.168.1.88:8080 ESTABLISHED
      

The second method only shows the proxy currently in use. If more than one proxy is configured in your environment, and you want to know all of them, you have to repeat the procedure above periodically to get the full list. Note that working in a Linux virtual machine on your office laptop with Windows OS can possibly help you circumvent the proxy issue.