Re: [squid-users] Trying to block IM's

Nor will it. Those IM applications are designed to work around firewalls
and blocking mechanisms. They'll even use port 80 to communicate, if they
have to.

If you really want to block IMs (it's debatable whether doing so is truly
worth the effort), you need to use an Intrustion Detection System like
snort.
The snort community has already developed the definitions/signatures to
use for blocking IMs. There is a learning curve with setting up snort,
but it's an incredibly sophisticated and powerful tool.

Hope this helps.

Tim Rainier

"Chris Boyd" <Chris.Boyd@usit.ie> wrote on 05/22/2006 11:47:29 AM:

> I'm trying to block IM's like MSN, Yahoo..etc...etc
> I've taken acl's from this list but it doesn't seem to be working.
>
> acl all src 0.0.0.0/0.0.0.0
> acl manager proto cache_object
> acl localhost src 127.0.0.1/255.255.255.255
> acl to_localhost dst 127.0.0.0/8
> acl SSL_ports port 443 563
> acl Safe_ports port 80 # http
> acl Safe_ports port 21 # ftp
> acl Safe_ports port 22 # ssh
> acl Safe_ports port 443 563 # https, snews
> acl Safe_ports port 70 # gopher
> acl Safe_ports port 210 # wais
> acl Safe_ports port 1025-65535 # unregistered ports
>
>
> acl Safe_ports port 280 # http-mgmt
> acl Safe_ports port 488 # gss-http
> acl Safe_ports port 591 # filemaker
> acl Safe_ports port 777 # multiling http
> acl Safe_ports port 4156
> acl CONNECT method CONNECT
> acl usit src 10.133.0.0/16 10.1.0.0/16
> acl ICQ url_regex -i .icq.com
> acl MSN req_mime_type ^application/x-msn-messenger$
> acl YAHOO url_regex .msg.yahoo.com
> acl CHAT url_regex -i webmessenger .webmessenger .messenger.*
> messenger.yahoo gateway.dll messenger.msn mirc icq.com go.icq
miranda-im.org
> acl WEBMSN url_regex -i .webmessenger.msn.com
> acl EMESS url_regex -i .e-messenger.net .webmessenger.msn.com/*
iloveim.com
> acl TALK url_regex -i .google.com/talk talk.google.com .google.
> com/talk* .google.*/talk*
> http_access allow manager usit
> http_access deny manager
> http_access deny !Safe_ports
> http_access allow CONNECT
> http_access allow localhost
> http_access allow usit
> http_access deny MSN
> http_access deny ICQ
> http_access deny YAHOO
> http_access deny CHAT
> http_access deny WEBMSN
> http_access deny EMESS
> http_access deny TALK
> http_access deny all
>
>
>
>
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Received on Mon May 22 2006 - 11:03:23 MDT