why this query cause ServFail

[Hillary Nelson]

Also should mention that our BIND is 9.9.8-P4, what confuses me here is
that the listed nameserver (129.114.13.18) is lame and our nameserver (
192.168.1.100) can't get any responses from it(see tcpdump above), why our
nameserver try other listed NS servers  instead sending 'ServFail' to the
client(10.79.1.6) ?
Any help will be greatly appreciated!

On Fri, Sep 9, 2016 at 1:07 PM, Hillary Nelson <nelsonhillary8 at gmail.com>
wrote:

> We've been seeing sporadic failure of resolve this name
> web1.production.tacc.utexas.edu from our nameserver.
>
> There are 6 NS listed for domain production.tacc.utexas.edu, two of the
> six don't seem to work(dc1.production.tacc.utexas.edu 129.114.13.17 and
> dc2.production.tacc.utexas.edu 129.114.13.18).
>
> If our nameserver hits the two and doesn't get any response, it sends
> 'ServFail' to client, shouldn't the our nameserver keeps trying the other
> four working nameservers listed for the domain ?
>
> Here is the tcpdump:
>
> 12:33:38.593146 IP 10.79.1.6.51980 > 192.168.1.100.53: 60950+ [1au] A?
> tas.tacc.utexas.edu. (48)
> 12:33:38.593573 IP 192.168.1.100.54985 > 129.114.13.18.53: 40455% [1au] A?
> web1.production.tacc.utexas.edu. (60)
> 12:33:43.593131 IP 10.79.1.6.51980 > 192.168.1.100.53: 60950+ [1au] A?
> tas.tacc.utexas.edu. (48)
> 12:33:47.593796 IP 192.168.1.100.49009 > 129.114.13.18.53: 38559% [1au] A?
> web1.production.tacc.utexas.edu. (60)
> 12:33:48.593234 IP 10.79.1.6.51980 > 192.168.1.100.53: 60950+ [1au] A?
> tas.tacc.utexas.edu. (48)
> 12:33:48.593583 IP 192.168.1.100.53 > 10.79.1.6.51980: 60950 ServFail
> 0/0/1 (48)
>
>
> Thanks in advance for your help!
>
>
>
>
>
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