I am using FreeBSD 4.9 as a routing/web/mail (pop3) server
I want to filter all clients that are using Yahoo Messenger.
All the solutions that I could find with Google are useless.
I even tried to filter all ports from 500 to 65500 and no use, Yahoo Messenger
I found a doc. that explains that filtering a certain IP addres from the authentification server
will stop users from using YM but the solution never worked. I filtered entire IP classes that I collected
using netstat -n or trafshow. No use.
Please tell me a solution, with ipfw rules if it's possible.
Please test te solution, because it's higly iprobable that it will work.
My outside interface it's fxp0 using IP 82.77.xxx.xxx
inside interface it's rl0 using IP 192.168.0.200
ports 21, 22, 25, 80, 110, 445, 1526 and 3389 MUST remain open to all connections.