RE: [squid-users] Blocking Yahoo! & MSN Messengers thru Squid.

> Trying to block Yahoo! Messenger & MSN Messenger without
> disallowing connections to TCP ports 443 & 563 or blocking
> Yahoo! Mail and HotMail in squid v2.5 stable1.

Hello

I believe you can run yahoo messenger through any port,
including 80. As I recall I was able to use yim on a machine
behind a firewall that allowed ONLY port 80 outbound traffic.

Perhaps you can do some dns trick to break resolution,
but this could probably be bypassed using a hosts file.

If it is a corporate line, maybe you could put a sniffer
on the traffic and publish the chats on a webserver, that would
likely get people to think twice about using it. Especially if
you have a written policy prohibiting use of such things.

Of course, this wouldn't be as easy if the line is encrypted.

Before I started my own business I worked for a large
corporation that had such a policy, and they fought hard to
keep the users under control. But the guy sitting in the
cubicle behind me would use the company phone to call his
kids EVERY DAY - across the country - and talk for 1-1/2
to 2 hours on company time, which no one ever seemed to
pay much attention to.

Take care,

--
Waitman C. Gobble, II
EMK Design  +1.7145222528 http://emkdesign.com
Yahoo Messenger ID               sleepy_cat_69