At 8/28/2002 10:45 AM, Rick Kemp wrote:
>Been trying to use Shorewall to stop the use of Instant Messenger
>services (specifically AOL's IM) on my LAN. Have not had any luck yet.
>Anyone know how I can?
Talking about Instant Messengers, let me talk about MSN Messenger.
Several months ago, a friend of mine wanted to block MSN Msg. Was easy:
block port tcp 1863.
But for my surprise, a certain MSN Msg version (I don't know if it persists
because I use Trillian for MSN connections) after an unsuccessful
connection to port 1863, it tries via port 80 (www). As any firewall it's
allowed to surf via port 80, MSN Mgr STILL WORKED.
The 'solution' was to block the entire subnet for 'messenger.hotmail.com'.