Our CyBlock Appliance offers the best coverage for blocking IM and Chat sites. The CyBlock Appliance can block the IM traffic as well as the sites to prevent the user from making a connection to the IM server.  To block IM with the CyBlock Appliance, first go to the Advanced Settings – Filter Settings – Block Web Protocols screen and check all the IM clients that you want to block.  Next, go to the Advanced Settings – Filter Settings – Block Web Categories screen and block the Chat category.  For even more coverage, you can also block the following URLs by placing them in a Custom Category or by adding them to the Chat category.

Yahoo IM: login.yahoo.com (Hardware and Software)

AOL IM: login.oscar.aol.com (Other Category)

MSN Messenger: login.live.com (Note: This site also is used for Hotmail login as well. So if you block the Hardware and Software category or this URL, you will block both MSN Messenger and Hotmail email).

To get the best filtering Chat/IM coverage with CyBlock Proxy or CyBlock ISA, block the Chat category and the sites listed above.