[squid-users] DNS lookup failure when transparent proxy

Hi,

I've installed squid version 2.5 release 9 on redhat linux fedora core 3 and
setup a proxy server (with 2 ethernet ports) between my LAN and the
internet.
I've successfully configured Squid so the proxy server runs transparently
and intercepts all http requests from clients on the LAN.
When I enter IP address's (including the IP address for google) in the
client's web browser URL, the pages are served fine, but when I enter a
domain name in the URL,
the browser returns the 'Page Cannot be displayed message'.

The client machine and proxy (in /etc/resolv.conf) both know our ISP
nameservers IP address and I've configured the proxy server firewall to
allow DNS lookups via UDP on port 53.

If the client browser is configured to use the proxy server (rather than
have it run transparently), DNS lookups work fine and domain name URL pages
are displayed.
I would however, really like to get DNS lookups working with a transparent
proxy setup.

I can't see it myself but would this involve changing settings in
squid.conf?.. or perhaps some form of iptables forwarding command for DNS
responses on UDP port 53? (ie to forward incoming
responses from the nameserver to the proxy back to the client machines on
the LAN).

Any possible solutions would be greatly appreciated.

Regards,

Steve
Received on Fri May 13 2005 - 05:09:25 MDT