Re: [squid-users] odd redirector behaviour

On 26/10/11 14:26, Brett Lymn wrote:
>
> Hi,
>
> We are running squid 3.1.15 on a couple of RHEL5 machines and using
> Websense for the web filtering. Mostly this is working fine but I have
> noticed an oddity when Websense blocks an element on a page sometimes.
> If I go to a site that is definitely blocked in its entirety then I do
> see the "this page is blocked" from websense which tells me the
> redirectors are working correctly. The problem I see is sometimes when
> there is a single element on a complex page is blocked (for example, an
> advert) then it looks like the whole page is redirected to the block
> page and the user is presented with a blank looking page. Our
> production servers are running the same version of Websense but use
> squid 2.7 stable 6 and we don't see the issue here.
>
> I cannot rule out websense stuffing something up but the logs look like
> it is doing the right thing both from websense and squid so I am
> wondering if there is some sort of issue with the redirection handling.
> I tried a debug 85,6 but that didn't show anything wrong as far as I can
> tell.
>

As I understand it Websense for 3.x works differently than for 2.x. Due
to the Websense patches on 2.x needed to use the URL-rewriter API for
content scanning. With 3.x it just uses ICAP.

If it is Websense, you should contact them about support. They have been
very restricted in what they will share with us about the integration
patches.

I think you can test if it is Websense by looking at the resulting page
source code and object URLs vs what should have been received without
the filtering. Blank pages are often a sign that the page itself is so
broken the browser can't cope. Could be broken at the web server right
at the start and the filter change is just enough to push it over into
browser failure.

Amos

-- 
Please be using
   Current Stable Squid 2.7.STABLE9 or 3.1.16
   Beta testers wanted for 3.2.0.13