Hi,


I've a squid proxy running in my network.I tried to block chat programs through many ways from the information I got from net.Anyway finally I could block chatting through IPTABLES with the command,

iptables -A FORWARD -s 192.168.0.40 -m state --state ESTABLISHED,RELATED -j REJECT

to block chatting for the client 192.168.0.40.

This blocked chatting but I found that this will disallow me to access FTP and POP as well. So I specifically opened ftp port, and address of my mail server for the client. As if now everything is working fine. But I do not know if my iptables command will block anything else.Please let me know if this will lead to me a problem later.

Thanking you in advance,

Jomy

I think I found a better way to stop the chat apps. Look through the squid logs for the user in questions, looking for sites related to the chat client. They all use servers to connect to their networks. For example, using squidGuard, I blocked *.icq.com, and all icq traffic came to a halt on our network. Additionally, block the websites that users download these virus-fest apps from.