I am using Fedora core 8 as a gateway server. In my gateway server I have configured DHCP, DNS, Squid Proxy & it will act as router (IPForwarding). I am connecting internet using Linksys broadband router in that router NAT enabled. If any client connects to my gateway server they can able to access the internet directly because in router NAT enabled and in getaway server IP-Forwarding enabled.
I enable IP-Forwarding in gateway server for VPN Routing.
From any client pc if we ping google.com or any website I am getting icmp reply by default, so user not using the proxy server they accessing the internet directly. This problem occurs due to enable NAT in router and IPforwarding in gateway server.
Gateway server NIC details:
eth0: 192.168.0.0/24 (For local connection)
eth1: 192.168.20.0/24 (For broadband connection)
This is my requirement:
1) I want to block the user to access the internet directly, by using firewall. (without disable the NAT and IP-Forwarding)
2) I want to allow one particular ip to access the internet directly via gateway server using NAT.
3) Allow one particular website (eg. MSDN site) to all via NAT in gateway server.