Re: Summary of Transparent proxy/How-to

Erik T. Brandsberg wrote:

> sites that require the Host field. The main drawback of this is that
> squid uses "http://123.123.123.123/url" for caching, thus sites with
> several IP addresses will get redundantly cached, reducing hit rates.
> Virtual configurations override the host header in the stock squid,
> thus it won't fill in the server name in the rewritten URL.

If you haven't noticed already, this breaks virtual servers using the
Host: header (one IP but many server names). And Squid running as a
transparent proxy needs to have both Host: header support, and virtual
IP support enabled (which is not possible in stock Squid 1.1.18), or the
users will be very confused (and angry) when accessing virtual servers.

The problem is that if you have two servers, both using the same IP
www.domain-a.com a.b.c.d
www.domain-b.com a.b.c.d

Then if one of your "transparent proxied" users requests
http://www.domain-a.com/ it will be cached as http://a.b.c.d/. If then
another user requests www.domain-b.com it will generade a cache hit on
http://a.b.c.d/ and the user will see the www.domain-a.com page instead.

And if you only enable Host: header support, you will break older
clients which don't use the Host: header.

So you need both fully working, in order to keep your customers happy.

---
Henrik Nordström