[CentOS] how do I find out which nameserver returns a DNS query? {SOLVED}

Rudi Ahlers Rudi at SoftDux.com
Tue Jul 8 07:50:37 UTC 2008

Jonathan Wright wrote:
> Rudi Ahlers wrote:
>> Hi all
>> If I do a "dig mydomain.co.za" from a Linux server, how do I know 
>> which DNS nameserver returns the queries?
>> I seem to have a faulty DNS server, but can't see which one, so I 
>> want to find out which nameserver (if there's 4 - ns1.myserver, 
>> ns2.myserver, ns3.myserver & ns4.myserver) returns the queries?
> Try the +trace option - it will get dig to output the details of each 
> request on a full resolution (bypassing any local name-server and 
> performing it's own lookup from the root servers onwards).
> e.g.  dig +trace mydomain.co.za
It doesn't lik me :(

dig +trace cp.hostfactor.co.za

; <<>> DiG 9.3.3rc2 <<>> +trace cp.hostfactor.co.za
;; global options:  printcmd
.                       36416   IN      NS      E.ROOT-SERVERS.NET.
.                       36416   IN      NS      M.ROOT-SERVERS.NET.
.                       36416   IN      NS      G.ROOT-SERVERS.NET.
.                       36416   IN      NS      B.ROOT-SERVERS.NET.
.                       36416   IN      NS      F.ROOT-SERVERS.NET.
.                       36416   IN      NS      L.ROOT-SERVERS.NET.
.                       36416   IN      NS      K.ROOT-SERVERS.NET.
.                       36416   IN      NS      A.ROOT-SERVERS.NET.
.                       36416   IN      NS      D.ROOT-SERVERS.NET.
.                       36416   IN      NS      H.ROOT-SERVERS.NET.
.                       36416   IN      NS      I.ROOT-SERVERS.NET.
.                       36416   IN      NS      J.ROOT-SERVERS.NET.
.                       36416   IN      NS      C.ROOT-SERVERS.NET.
;; Received 228 bytes from in 49 ms

Segmentation fault

hehe. That's a nice trick though, I noticed after the 3rd attempt that 
it goes to our domain registrars nameservers, then segment faults again. 
But I'm sure this will do the trick

On another server it worked as expected, and I could see which 
nameserver returned the query. My reason for looking for this is that we 
run 2 nameservers, one on Linux & 1 on Windows - serving the same 
domain, but it's not synced, so I wanted to see what happens if records 
change on one server and not the other.


Kind Regards
Rudi Ahlers
CEO, SoftDux

Web:   http://www.SoftDux.com
Check out my technical blog, http://blog.softdux.com for Linux or other technical stuff, or visit http://www.WebHostingTalk.co.za for Web Hosting stuff

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