hi friends,
In my office there is a 15 pc local area network.
there is a LINKSYS router present for the interet connection .
I have installed a REDHAT centos on one machine and setup a squid server (proxy) for restriction over internet.
Then in the linksys router configuration i have given access to only my proxy server so that clients can not directly connect to the internet through router.
Then the client machine i put the gateway as the ip address of proxy server.
but internet is not accessible to the clients with this setting.
will you please help me to solve this problem?

I am not sure how you are blocking the clients from the linksys router, do all of the clients get IP addresses from the router? can they ping the proxy server?