what does dig +trace do?

Marc Lampo marc.lampo at eurid.eu
Tue Aug 30 12:25:59 UTC 2011


"+trace" makes dig behave like it were a caching name server with an empty 
cache, so to speak.

What strikes me as odd is that the first query does return 4 (internal) root 
servers, but no glue records ?
Given those root name servers, do you have A-records for root[1234] in your 
root zone ?

Kind regards,

Marc Lampo

-----Original Message-----
From: Tom Schmitt [mailto:TomSchmitt at gmx.de]
Sent: 30 August 2011 01:57 PM
To: bind-users
Subject: what does dig +trace do?


I have a question: What does dig +trace exactly do?

The reason for my question is:
I have a internal-only DNS in our company with my own root-zone. And normaly 
all things are fine. But when there is an issue I would like to analyze with 
dig +trace, the command fails.

If I do dig +trace example.com

I get something like this:

; <<>> DiG 9.8.0-P4 <<>> +trace example.com
;; global options: +cmd
.                       10800   IN      NS      root1.
.                       10800   IN      NS      root2.
.                       10800   IN      NS      root3.
.                       10800   IN      NS      root4.
;; Received 159 bytes from in 1 ms

;; connection timed out; no servers could be reached

I don't understand why there is a timeout. Next zone on the trace should be 
the com. domain which is hosted on the same servers as the rootzone.

I don't see any DNS-problems at all, only the +trace-option is behaving 
weird. Can anybode tell me why? What does this option what normal DNS 
queries don't do?


NEU: FreePhone - 0ct/min Handyspartarif mit Geld-zurück-Garantie!Jetzt 
informieren: http://www.gmx.net/de/go/freephone

More information about the bind-users mailing list