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I have configured a DNS served in Ubuntu 12.04, the configuration of my zone is as follows.

$ORIGIN arturo.com.
$TTL 86400 ;
@ IN SOA ns.arturo.com. mail.arturo.com. 
(   
  2 ;
  6H ;
  1H;
  2W;
  3H;
)
 @  NS ns.arturo.com.

 ns  A  192.168.1.72

alvarado.com A 192.168.1.72

It works really well, but here is the thing: I added this DNS to a Windows machine to see it doing its job. It solved ns.artuto.com and alvarado.com.arturo.com. But this DNS does not have to solve any internet address, surprisingly, it does. How is that possible? I havent configured any forwarders in maned.conf.options for this to happen. Any ideas?

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  • I forgot to mention that im really sure that I have no other DNS configured in the Windows machine I mentioned above. The DNS answer (nslookup) comes from this server that I configured.
    – Arturo
    May 24, 2013 at 6:22

1 Answer 1

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By default, BIND will act as a recursive nameserver and find DNS information using the glue file to find the root servers, the root servers to find the nameserver for a domain, and then that nameserver to get the result. It doesn't need to forward to do this (and this is typically what the nameserver to which you forward would do).

If you want to disable this behaviour, you can specify this configuration directive (in named.conf):

options {
    recursion no;
};

If you already have an options section, just add the directive to it.

Also, for reference, you can use dig (in unix) or nslookup (in windows) to test name resolution without having to change the system-wide DNS settings on your test box:

~/foo $ dig @1.1.1.1 in a test.domain.net


C:\> nslookup - 1.1.1.1
nslookup> test.domain.net
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  • Wow thanx, that was a really accurate answer. But what is the use of forwarders then? I thought they were used when the server is not authoritative and does not have the answer in its cache. According to net.cmu.edu/groups/netdev/docs/bind9/Bv9ARM.ch06.html
    – Arturo
    May 24, 2013 at 16:33
  • Forwarders are there for you to delegate the recursive lookup of data you don't have to another server, which will use its root hints and query successive nameservers to fetch the result for you. May 25, 2013 at 8:21

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