RE: [K12OSN] Instant Messanger

[k12osn collinsoft com]

On Tue, 30 Sep 2003, Caleb Wagnon wrote:

> Nicholas Santiago said:
> Really? Because I have found that many of these messengers now use port 80
> or scan for another open port when the default port is blocked. I used to
> have them all blocked at our firewall until they started using 80 and
> scanning for other ports. If you're blocking them successfully....is there
> somehow you could find it in your heart to let me know which ports you are
> blocking exactly? That would be greatly appreciated!!

Transparently proxy port 80, that will usually stop it. You can also just 
block port 80 and make everyone use a Proxy Server, but then the IM 
clients might know what to do if you set them to use a proxy server.

I've also started blocking access to the actualy machines used with AIM 
and Yahoo!.

-- 
Ryan Collins