Proxy test tools or results available?

["Stout, Bill" <StoutB () pios com>]

What proxy test tools or results exist?

For the sake of a protected application server, I'd like to throw a
collection of valid and random commands through, and examine what got
through.  I'd like to know how different specific application specific
proxies really are from generic proxies, and that for example non-http
sessions can't be made through the http proxy.

To accurately test what is passed may require a pair of tools, or a tool
split into a netcat-like command generator spewing commands through the
proxy and a (verbose logging) target (netcat again?) on the inside to
show what got through. 

It would be nice if a test system were a dual-nic box that connected to
both sides of a standalone proxy server.  Could serve to test caching
proxies, latency, etc.

Bill Stout