Reg: Blocking Yahoo messanger in firewall

Hi,

I have to block Yahoo messanger in internal firewall Netscreen or in External Firewall PIX. Can any one Help me.

easiest way to do this is to block the following ports yahoo messenger uses for its services:

Chat & Messenger TCP Port 5050
File Transfer TCP Port 80
Voice Chat UDP 5000-5010, TCP 5000-5001
WebCam TCP Port 5100
Super Webcam TCP Port 5100
P2P Instant Messages TCP Port 5101

but be aware, some ports might be used for other common services like HTTP etc, so give it a good thought while trying to block them, or else you might be blocking yourself out from the entire web

Hi,

I cannot do this by IP address as half dozen different subnets (ranging from a couple of /24's to a /19),all used for the yahoo messenger servers. So I have to use Any detination and I blocked all the ports except 80 as it used for HTTP. If i open 80, Yahoo messanger connecting through 80.

Do you have ISA server installed? If yes, you can filter this messanger for set of clients using Application layer filter.

(or)

In PIX you can buy AddOns to filter these type. Checkout PIX firewall website.

Hi,

we Don't have the ISA server. What is that Addons can you explain me.

If you have control over a Cisco router at your edge, you can use the IOS firewall features to block non-http traffic over port 80.

Take a look at www.cisco.com/en/US/products/sw/iosswrel...00aecd802efa46.shtml