I have a user wich IP is 192.168.0.12 and gateway 192.168.0.4. I want block MSN Messenger for this user. I have a Gateway server (it does NAT 192.168.0.0/24 to 188.8.131.52). I'm using linux redhat 9.0. External interface (INTERNET) is eth0, internal is eth1 (LAN). I tried putting this in my FIREWALL script, just testing, but it doesn't block anything:
iptables -A FORWARD -p TCP --dport 1863 -j REJECT
iptables -A FORWARD -d 184.108.40.206/24 -j REJECT
How can i do, using iptables, to block MSN messenger for this specific user.???