detect Proxy on the network

[johnisccp]

Is there a way for me to detect if a proxy server or computer was install on the network?

[miheg]

Here's a description of some ways.

http://www.grape-info.com/doc/win2000srv/internet-gw/wpad/index.html

Cheers,

Michel

[johnisccp]

Michel,

Thanks for your reply but I do not wish to configure or install a proxy server. I want to find if someone who is not authorize to setup a proxy, setup one on the network.

[yjdabear]

Well, if you have some guesses/assumptions to the characteristics or flavor of the unauthorized proxy in *active* use, you can have measures like having a NetFlow reporting tool/RMON II probe alert you on certain traffic pattern (say, assuming all TCP port 3128 traffic are Squid Cache proxy) going over a certain rate or volume. For a proxy that's not talking much, what can you do? Sweeping port-scan your own IP ranges?