Reg: Blocking Yahoo messanger in firewall

try a third party blocking software like this one

www.freedownloadscenter.com/Utilities/Ac...e_s_TerminatorX.html

Hi,

Thanks for your advice.

In Netscreen Firewall . there are pre-define services which could be allowed or blocked. You will also find Yahoo Messenger services as a member . Just Block it

Hi,

For blocking yahoo messanger. If you block all the ports except port 80 yahoo messanger will take port 80 and you cannot block port 80 if you block your internet is down.

As My friend d_jabsd gave me a solution for it.

I block Yahoo, ICQ, AIM and MSN via DNS. Each program connects to a FQDN in the settings. Add dummy records to your internal DNS server so when the person attemtps to connect it routes them to a dead IP.

yahoo:
edit.messenger.yahoo.com
msg.edit.yahoo.com
msg.yahoo.com

icq:
login.icq.com

aol:
login.oscar.aol.com

msn:
messenger.hotmail.com

thse are the ones ive blocked. worked like a charm.

The same history for every enterprise, another alternative If you have a router with ios 2.3 try NBAR matching against msn traffic the idea I suggest is first try capturing only msn traffic by ethereal, then I think the frame beggining for all msn traffic frames starts by the same ascii paterns, try capturing it, and by NBAR match against data payload of every frame traversing the router examining the payload agains a match, if there is a match police it as drop, as an ACL.

Its only an Idea, I dont know if it even works, I have no time to test it, so if you have time, try it, conceptually it must.