Re: Name resolver problem after upgrade from woody to sarge
[This message has also been posted to linux.debian.user.]
In article <4HGKT-43k-1@gated-at.bofh.it>, Mats Bengtsson wrote:
> Hi,
>
> I have just upgraded my machine at home from woody to sarge and now the
> name resolution doesn't work anymore. To be more precise, programs such
> as Mozilla or lynx don't manage to lookup any names, but i can use host
> or dig or nslookup (or even socket.gethostbyname(...) in Python) without
My impression is Mozilla only reads /etc/resolv.conf
once, when it's launched. If you change resolv.conf,
you have to exit mozilla and start a new one.
I haven't seen Lynx have that problem.
> problems. Also, once I have looked up a name using host, for example,
> then Mozilla can also find it, at least for some minutes of time.
In that case, I would look for a problem with the forwarder
(dns cache) that you're pointing at with resolv.conf.
> I have tried looking in different documents and HOWTO:s and Google but
> haven't found anything really related. Also, I don't know the inner
> workings of name resolution in Linux, so I may have missed something
> obvious.
>
> Some facts on my setup:
> - I use an ADSL connection with a combined ADSL modem/router configured
> as a DNS relay.
> - ifup seems to detect this setup correctly and writes
> nameserver 192.168.1.1
> in /etc/resolv.conf
Is there really a name server at 192.168.1.1? Does it work? Try
host kernel.org 192.168.1.1
and see.
> - Since I only have 2 machines connected to the router, I haven't setup
> any DNS for my private network and have simply added a line
> 192.168.1.2 MatsPC
> in /etc/hosts
>
> At the moment, I don't really have any clue on where to search, so any
> hints are welcome.
While you're working on your home network, routers, resolv.conf,
ifup/down, etc, use a reliable name server on the public Internet.
After everything else is working, *then* worry about a local
forwarder. Maybe you don't need one. Don't assume the name server
you're told about by DHCP actually works.
There are still a lot of name servers around that answer all
queries from everywhere. They'll die (or be secured) if somebody
publishes software that uses them by default, but short of that
the potential for abuse isn't too bad. Pick half a dozen of
your favorite ISPs and look up their name servers in whois.
Try all the listed name servers. Some will work, some won't.
Chances are you'll find at least two that answer queries about
unrelated domains as well. A certain large telco on the West
coast of the US, that doesn't have any network tech support for
its residential DSL customers, has one. Perhaps the last technical
person forgot to shut it off when they laid her or him off.
The largest cable TV operator in the US, who happens also to be
#2 on the Spamhaus.org list, has another. And the #1 spam supporter
worldwide (see spamhaus top 10) has two more.
Cameron
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