[ubuntu-uk] Squid proxy box with serious IPv6 DNS problem...

Alan Bell alan.bell at theopenlearningcentre.com
Thu Mar 26 22:15:39 GMT 2009

I think from the description the squid thing is actually a red herring. 
(to mix a fishy metaphore). It sounds like your proxy server is not 
reliably resolving DNS when using IPV6. You will probably see this 
problem if you run firefox on the server.

not sure how you turned off IPV6, one way is to edit
/ /etc/modprobe.d/aliases
and edit it to have this line:
/alias net-pf-10 off ipv6

a better solution would be to fix the actual problem, one way might be 
to point your proxy at openDNS which works fine with v6. I suspect the 
DHCP server is pointing your box at a bad router for DNS queries.


LeeGroups wrote:
> Chaps...
> Over the last couple of days I've been trying to build a proxy box for a 
> load of Windows PCs, using Squid on Ubuntu server 8.04.
> I've had a few problems with it due to the wild/wacky filtered internet 
> connection we have there, but now I've hit a massive brick wall...
> Using an upstream proxy config Apt can get out to the internet fine, 
> download and update the OS.
> However, Squid can't resolve any DNS loopups... it just fails a few 
> minutes after loading.
> Doing a wget of a known file like the Google index page also fails with 
> a unresolved DNS error.
> However, (after much much much reading) using the -4 option of wget, to 
> force it to use IPv4, it works fine, resolves the Google address and 
> downloads the index page and saves it.
> I've blacklisted the IPv6 service, but wget (and Squid) still doesn't 
> work without the -4 option, so I guess bits of IPv6 are still hiding 
> there somewhere....
> My question is - How do I fix this bloomin' thing?  I've been googling 
> for hours with only the -4 option to show for it... and I really need to 
> get this this working for Friday afternoon...  Otherwise bad Windows 
> things may happen...
> Cheers,
> Lee

More information about the ubuntu-uk mailing list