This thread will give you an idea
http://www.linuxquestions.org/questi...ight=amsn+port
Basically they recommend adding these rules below. I'm not familiar with using lokkit though there must be a few that are, as I don't know how to use Lokkit which I assume is what you've got as it's red hat you're using you can type them in at the prompt (might have to change RH-Lokkit-0-50-INPUT to what's appropriate for you or just change it to INPUT) or save them in a text file and make it executable
iptables -A RH-Lokkit-0-50-INPUT -p udp -m udp -s 0/0 --sport 6890:6895 -d 0/0 --dport 6890:6895 -i eth0 -j ACCEPT
iptables -A RH-Lokkit-0-50-INPUT -p tcp -m tcp -s 0/0 --sport 6890:6895 -d 0/0 --dport 6890:6895 -i eth0 -j ACCEPT
Someone that knows Lokkit might eventually come along, if you can't get it going I'd give it time and start a new thread like "How to I add these rules to using Lokkit" or something like that