Log of unresolved DNS queries?

activeco at home.nl activeco at home.nl
Sun Dec 22 23:49:24 UTC 2002

On 22 Dec 2002 23:21:04 -0000, Simon Waters
<Simon at wretched.demon.co.uk> wrote:

>activeco at home.nl wrote:
>> Does anyone know of a possibility to get a log of unresolved dns
>> queries (especially .coms) for any time period, preferably from a
>> root server; hourly, daily, doesn't matter?
>> Any address, tool, anything which could return asked non-existent
>> locations.
>Packet tracing like ethereal should easily catch all NXDOMAIN
>answers whizzing through an interfaces I would have thought.

Thanks Simon.
Could you provide more info, please?

>I don't understand the root server reference, do you mean an
>authoritative server? 
>The root servers would not know about failed ".com" lookup's as
>they would refer such a request to the GTLD servers, who would
>return NXDOMAIN.

Well, I am the absolute amateur in this, so the most of the
terminology I am not familiar with.
I met with the "topic"  today, did some research and tought that
all the DNS requests go hierarchicaly towards highest root
servers for resolving.
So I guessed all non-existing domain name's requests must end there. 
Please excuse my greeness. :-)

>I assume "unresolved" means none existent domains, which DO
>resolve, to a negative answer. i.e. an authoritative server says
>it doesn't exist.


>It is not uncommon to have reverse lookups fail due to erroneous
>configurations, BIND 9 lists some of these as lame, which can be

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