Hi all,
I am having problem while using transprent squid on cenos 5.7.
I configured the transparent squid proxy server on Centos 5.7.
I redirected all the port 80 traffic to squid by redirecting it to port 3128 in prerouting rule, it works fine on the client web browsers.
The problem is that some applications on client like utorrent, skype etc cannot connect to internet using this transparent squid. If I allow the ip_forwarding in centos, these applications use centos as a router and bypass the squid. If ip_forwarding is disabled, these applications fail to go to internet.
Can someone help me by telling some iptables prerouting rules to redirect all traffic to squid.
This is very important for me, Thanks in advance.

Try the following: http://www.karlrupp.net/en/computer/nat_tutorial Specifically, look at the section under the heading Applications, which has a subsection on Transparent Proxying.