We just begun to dig the proxy server. Yes, read Craig's book.

The general impression seems to be that the proxy be good for HTTP, but
not for others.

We'd like to track when which users use which applications for audit
purpose. Since our outgoing traffic is nated, when the appliation server
is located in a partner's place, we don't have way to audit the access.
Our firewall is not BM, so no user infomation can be recorded. Also the
clent IP is got from DHCP.

The Generic proxy seems having such capibilities. However,it does not
have the log capibilites like HTTP.

Am I lost? Is there any better and easy way to do this?