How to disable mIRC and other chat client with iptables

[Gerry Doris]

Myanmar Linux Boy wrote:
> Dear All,
>  I am new to linux.
>  I want to disable chat with iptables so that nobody can use chat with
> mIRC with   LAN. Because every students are chatting all the time.
>  I am using Red Hat 9 and Squid.
>  They use port 443 and 6667 to chat with mIRC
>  How can I write firewall rules.
> 
> Any help is appreciated
> Myanmar Linux Boy
> 
You can write all the rules yourself but that's a real pain in the 
bottom.  I've been using Monmotha's firewall script for years without 
problems.  There are also other similar scripts available but I've 
gotten used to Monmotha's.

You can download it from

http://monmotha.mplug.org/firewall/firewall/2.3/rc.firewall-2.3.8-pre9

Scroll past all the verbage in the top until you get to Main Options. 
You need to edit those to allow the ports you want, identify which 
eth0/1 is your internal and external interface and make sure you have 
the correct internal lan shown.

The options are described here

http://www.hosef.org/wiki/index.php/MonMothaReferenceGuide


Have fun!!!