Thanks all, have this sorted now. IPCop seems to allow for three custom chains / tables (are they still called chains when using IPTables?) CUSTOMINPUT, CUSTOMFORWARD & CUSTOMOUTPUT set up in /etc/rc.d/rc.local.
I accomplished what I wanted by using the lines: /sbin/iptables -F CUSTOMFORWARD /sbin/iptables -A CUSTOMFORWARD -s localhost -j ACCEPT /sbin/iptables -A CUSTOMFORWARD -s 192.168.1.1 -j ACCEPT /sbin/iptables -A CUSTOMFORWARD -s 192.168.1.0/255.255.255.0 -j DROP Thus allowing everything from the server through, then rejecting everything else from the local network. Not sure if I needed line 2. Now clients *must* have their internet settings to use 192.168.1.1 as proxy to access the internet. Cheers Kerry.
