RE: Blocking IM

If you're using the SurfControl product for ISA, there isn't much capability to 
block based on application, but you should be able to block by port through ISA 
itself.  I found the following about Yahoo IM below...
 
Another workaround I found useful was making the Yahoo IM exe an unwanted 
program through your AV product.  (Capabilities will vary of course)

Yahoo! Messenger services uses a variety of ports. 

Service         Ports   
Chat & Messenger        TCP Port 5050: Client Access only       
Insider/Room Lists      TCP Port 80: Client Access only         
File Transfer   TCP Port 80: Server Access.
Your ISP may block this port, as its used for web hosting.
You can change port in Messenger, Preferences, File Transfer.   
Voice Chat      UDP 5000-5010
TCP 5000-5001: Client Access
If UDP Fails, TCP will be used instead, see below.      
WebCam  TCP Port 5100: Client Access    
Super Webcam    TCP Port 5100: Server Access    
P2P Instant Messages    TCP Port 5101: Server Access
PMs between Buddys may not use the Yahoo! Server, but this is not a 
requirement.        

-----Original Message-----
From: Morales, David (Seta) [mailto:David_Morales@onr.navy.mil]
Sent: Tuesday, December 06, 2005 2:51 PM
To: firewalls@securityfocus.com
Cc: Amiryar, Edris (Seta)
Subject: Blocking IM



We are blocking IM at the Firewall (juniper 5200) and through Surf-control (Web 
Filtering product, but we are still able to connect to Yahoo IM. Has anyone 
been able to do this successfully? And, does anyone have a list of ports to 
block so we cannot get to this IM?

Thanks in advance,

David Morales

moraled@onr.navy.mil