Block MSn messenger and yahoo messenger

[shani]

Hi Every body,

i am using redhat linux 8.0 on my system and i have already implemented only NAT on it , now i wanted to block Msn messenger and yahoo messenger through this nat.
following is my NAT script.

((iptables=/sbin/iptables
 iptables --flush -t nat
iptables --table nat --append POSTROUTING --out-interface eth1 -j MASQUERADE
iptables --append FORWARD --in-interface eth0 -j ACCEPT
echo 1 > /proc/sys/net/ipv4/ip_forward))))

thanks

[Ricky]

You have to find out that what ports and what urls ie. servers are used by those IMs and then block them..
For further we had a discussion already on it ..
see Blocking yahoo and msn messenger