From owner-freebsd-security Tue Mar 27 22: 6: 6 2001 Delivered-To: freebsd-security@freebsd.org Received: from point.osg.gov.bc.ca (point.osg.gov.bc.ca [142.32.102.44]) by hub.freebsd.org (Postfix) with ESMTP id E656137B71A for ; Tue, 27 Mar 2001 22:06:03 -0800 (PST) (envelope-from Cy.Schubert@uumail.gov.bc.ca) Received: (from daemon@localhost) by point.osg.gov.bc.ca (8.8.7/8.8.8) id WAA14183; Tue, 27 Mar 2001 22:04:55 -0800 Received: from passer.osg.gov.bc.ca(142.32.110.29) via SMTP by point.osg.gov.bc.ca, id smtpda14181; Tue Mar 27 22:04:45 2001 Received: (from uucp@localhost) by passer.osg.gov.bc.ca (8.11.2/8.9.1) id f2S64ZJ72995; Tue, 27 Mar 2001 22:04:35 -0800 (PST) Received: from cwsys9.cwsent.com(10.2.2.1), claiming to be "cwsys.cwsent.com" via SMTP by passer9.cwsent.com, id smtpdz72987; Tue Mar 27 22:04:13 2001 Received: (from uucp@localhost) by cwsys.cwsent.com (8.11.3/8.9.1) id f2S648R14405; Tue, 27 Mar 2001 22:04:08 -0800 (PST) Message-Id: <200103280604.f2S648R14405@cwsys.cwsent.com> Received: from localhost.cwsent.com(127.0.0.1), claiming to be "cwsys" via SMTP by localhost.cwsent.com, id smtpdc14400; Tue Mar 27 22:03:37 2001 X-Mailer: exmh version 2.3.1 01/18/2001 with nmh-1.0.4 Reply-To: Cy Schubert - ITSD Open Systems Group From: Cy Schubert - ITSD Open Systems Group X-Sender: schubert To: Olivier Nicole Cc: uknowho@n0mansland.net, freebsd-security@FreeBSD.ORG Subject: Re: Filtering inappropriate content In-reply-to: Your message of "Wed, 28 Mar 2001 11:05:52 +0700." <200103280405.LAA16283@banyan.cs.ait.ac.th> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Tue, 27 Mar 2001 22:03:36 -0800 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org In message <200103280405.LAA16283@banyan.cs.ait.ac.th>, Olivier Nicole writes: > >The organization is looking to filter web content only. Apolgies for > >the confusion. > > Squid has some rules to do contents filtering I guess. I tried it. Squid is not all that effective. For example, matching expressions can be found in perfectly legitimate URL's, e.g. a sun.com web page has the character string "sex" in it (I think it was a Virtual Adrien component called RICHPsex), so my filter blocked it. I'm sure that operators of web sites that you want to block could name their files and directories with non-offending names, bypassing your filter. A squid filter may not have the desired effect. The only solution I can think of that works is to subscribe to a service that maintains a database of offending sites. Cisco routers are able to query a system that serves data from databases provided by vendors of this service. Many of these databases block by IP address rather than FQDN. Some even block by network address because operators of these sites have been known to move their systems to different IP addresses on the same network to circumvent filters based on IP address. Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 Team Leader, Sun/Alpha Team Internet: Cy.Schubert@osg.gov.bc.ca Open Systems Group, ITSD, ISTA Province of BC To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message