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I'm setting up a local network and have configured a DNS server. I can resolve hostnames by querying the DNS server, but no programs can look them up.

I uninstalled libnss-mdns and removed avahi-daemon and even rebooted afterwards.

Here are some examples:

root@cloud2:~# host has address
root@cloud2:~# ping
ping: unknown host

root@cloud2:~# grep hosts /etc/nsswitch.conf 
hosts:          files dns

my ntp server is configured for, but all I get is nxdomain on ntpq

any ideas?


This also applies to external DNS entries. I have my router both as a DNS forwarder on the custom DNS server and as an entry in resolvconf.


root@cloud2:~# host | head has address has address has address has address has address has address has address has address has address has address
root@cloud2:~# traceroute Temporary failure in name resolution
Cannot handle "host" cmdline arg `' on position 1 (argc 1)
share|improve this question
Odd. Please add the content of your /etc/resolv.conf file. Also mention which Ubuntu release you are running. – jdthood Jan 25 '13 at 12:56
DNS cache such as named or sssd caching negative lookups? – Steve-o Jan 25 '13 at 14:53
@Steve-o I had looked for DNS caching, I've been burned plenty of times by nscd in the past so that's a good suggestion :-) – zje Jan 25 '13 at 16:45
@jdthood Good suggestion! It was resolv.conf that was the culprit - see answer below – zje Jan 25 '13 at 16:46
up vote 4 down vote accepted

This was on Ubuntu server 12.04 LTS and Ubuntu 12.04 LTS

Thanks all for the help. Turns out to be a result of a difference in the way host and the glibc resolver read /etc/resolv.conf.

I was managing resolv.conf with a puppet module that edited the appropriate files in /etc/resolvconf/resolv.conf.d/.

Said puppet module resulted in an /etc/resolv.conf that looked like this:



with a space at the beginning of each line. After removing these spaces, I was able to resolve with both ping and manual lookups (host/nslookup/etc...)

I could've sworn that I've had those spaces on other OSes with no issues, but I just tried on a SL6.3 box and it caused the same behavior.

Thanks for your help and sorry for the trouble!

share|improve this answer
I don't see any unusual spaces in the earlier resolv.conf. – jdthood Jan 26 '13 at 6:56
By the way, is this a custom Puppet module or one you got from somewhere else? If the latter then we should see to it that the bug gets fixed upstream. – jdthood Jan 26 '13 at 6:58
The unsual spaces are leading spaces, which might be tricky to see given the way the gray boxes are. (I realize you've probably noticed, but I want to leave this question for posterity). Also, this is what I baesd my module on:, but remember that ubuntu uses the resolvconf service - so I edited /etc/resolvconf/resolv.conf.d/head I'm putting a comment on that site... – zje Jan 26 '13 at 17:29
I have edited the answer (pending acceptance) so as to make it clearer that there are spaces at the beginnings of the lines. I consider this to be a shortcoming in the glibc resolver; it should ignore leading whitespace, especially if host does so. – jdthood Jan 26 '13 at 21:25
I left a comment on that site too. I also filed a wish in the Debian BTS (#699061) requesting that leading whitespace be ignored in resolv.conf. – jdthood Jan 26 '13 at 22:13

You need to supply dns config for each connection type you have.

Network Manager is your friend (or if you are using DHCP, then configure your DNS there)

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