Re: Transparent proxy

Pawel Pierscionek wrote:
> What are the disadvantages of transparent proxying ?
> Do I loose something. Does it behave (for customer) like setting proxy in
> the bowser.

Obviously it means you have to set up your router so that all your web
access will be routed through your squid. Normally (unless you fiddle with
Cisco redirector or suchlike) this means you have to pass _all_ your IP
traffic through your web proxy. As well as performance issues, this has
wider implications like a 24x7 service of your web cache box.

Considering the box will be doing the proxying, making it the chief gateway
to the internet _as_well_ may add unnecessary latency to non-web use. So if
you can _avoid_ doing transparent proxying then you should.

Transparent proxying is also always going to be more problematic than normal
proxying. It breaks assumptions of both the client and the target server and
you have to hope that in the end everything does the right thing. Many
people have transparent proxying working fine, but inevitably, more
complexity means more things can go wrong :-). Also debugging transparent
proxying is more problematic due to its transparent nature.

So basically, use it if you have to. Don't if you can avoid it. If you want
to be able to change the configuration "transparently", then use proxy auto
configuration scripts instead (see the squid FAQ), although those aren't
without problems too.

Transparent proxying does avoid changeover problems, but IMHO there are
simpler ways to deal with that - tell people to use the proxy, and after a
month block all outbound port 80 accesses on your router :-).

This reminds me of something I would like a definitive answer for: does IE4
support proxy auto-configuration reliably i.e. now that I've got round to
writing a script should I simply say that all IE4 users should not bother
trying to use it?

Ta,

Jifl

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