Croy, Nathan wrote:
It's not the same as making a web proxy configuration mandatory. The redirection makes you lose auditing information (the source IP).[...] IANANG (...network guru), but I think it is possible to set up an iptables/ipchains firewall such that any requests from the inside, destined to port 80, would be redirected to an internal host (the proxy), and any requests from the proxy's IP would be allowed to pass. The web client is none the wiser, thus transparent proxying.
-- André Carezia Eng. de Telecomunicações Carezia Consultoria - www.carezia.eng.br