Re: [squid-users] reverse DNS by squid when using parent proxy

From: Henrik Nordstrom <>
Date: Thu, 14 Feb 2002 13:23:08 +0100

Squid only looks up DNS data if it has to by configuration. In this
case if there is domain based access controls.

For example, the following config would trigger a reverse lookup of
IP URL:s even if inside a parent and firewalled...

never_direct allow all
acl local_domain dstdomain
always_direct allow local_domain

If you are in a disconnected network where you do not have access to
Internet other than via proxies then it is highly recommended that
you have a local DNS root to make sure Internet lookups gets rejected
quickly. If you don't then your DNS servers will try to contact the

Henrik Nordström
Squid Developer

On Thursday 14 February 2002 10.37, wrote:
> Hi,
> I have found that squid performs a reverse DNS lookup if an ip
> address is given as the url - even when a parent proxy is
> configured. It was my understanding that all requests would be
> forwarded to the parent. Is this default behaviour? Is there a way
> of stopping this so that squid will forward everything to the
> parent - regardless?
> I have an acl that uses dstdomain, so I realise that a reverse
> lookup will be performed - but why does this happen if a parent
> proxy is reachable?
> what's going on! help!
> tia

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Received on Thu Feb 14 2002 - 05:30:08 MST

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