Re: how to block web messenger services

[Javier Reyna Padilla <jreyna () onlinet com mx>]

The only wat to stop it is filtering http request, yo can do it as 
everybody has told you with a proxy or with an URL filtering. If you wan 
to use open source you can use squid with dansguardian to filter url, or 
just with squid. There are several commercial URL firlters than can do 
this job fine.

If you don't want to use a proxy, then you can avoid this usind an IDS, 
but this one has to be able to send even TCP Resets or modify rules on 
Firewall (SNORT!!!!!!) or you can use a IPS and block the request for IM 
via http. The most time this rules are RegEx including the URL for the 
IM destination.


Regards.

Javier Reyna Padilla
CCSA CCSE WCSE.
Departamento de Seguridad Informatica
Onlinet SA de CV
www.onlinet.com.mx



K. Brian Kelley wrote:
> You can chase your tail by trying to keep up with the ever changing IP addresses or go for a security appliance designed to 
> filter such traffic. I'd advise the latter if you can afford it.
>
>  
> K. Brian Kelley 
> Author: Start to Finish Guide to SQL Server Performance Monitoring
> Contributing Author: Best of SQLServerCentral.com Series
> Regular Columnist, SQLServerCentral.com and SQL Server Standard Magazine
> http://www.truthsolutions.com/
> http://blogs.sqlservercentral.com/blogs/brian_kelley/default.aspx
>
>
> ----- Original Message ----
> From: "nawalmiftahi () gmail com" <nawalmiftahi () gmail com>
> To: security-basics () securityfocus com
> Sent: Tuesday, March 20, 2007 7:25:50 AM
> Subject: how to block web messenger services
>
>
> Hi all , 
>    i am a security admin,yahoo messenger and other chat services are blocked on our network, but we can access them thru web(ebuddy) , i wanted to know how can we make sure that these chat services (yahoo messenger, icq, msn messeger ) cannot be accessed through web as well , i mean how to block them.
> thanks
>
>
>  
> ____________________________________________________________________________________
> Don't get soaked.  Take a quick peek at the forecast
> with the Yahoo! Search weather shortcut.
> http://tools.search.yahoo.com/shortcuts/#loc_weather