dig printout doesn't appear to match reality

[Frank Bulk]

It appears that dig is printing results that it attributes to the wrong
server.

While troubleshooting an inconsistent NS issue (upstream from us), a trace
(at the end of this message) shows that DNS3.UIOWA.EDU listed two NS
records, when in fact, if you query DNS3.UIOWA.EDU for the domain in
question it returns three NS records.  The results that were returned belong
to either DNS-2.IASTATE.EDU or DNS2.ICN.STATE.ia.us.

Why is dig attributing it to one NS server when it belongs to another?

Regards,

Frank

============================================================================
==
nagios:/etc/cron.daily# dig +trace NS sioux-center.k12.ia.us

; <<>> DiG 9.5.1-P1 <<>> +trace NS sioux-center.k12.ia.us
;; global options:  printcmd
.                       512780  IN      NS      b.root-servers.net.
.                       512780  IN      NS      e.root-servers.net.
.                       512780  IN      NS      f.root-servers.net.
.                       512780  IN      NS      m.root-servers.net.
.                       512780  IN      NS      g.root-servers.net.
.                       512780  IN      NS      k.root-servers.net.
.                       512780  IN      NS      l.root-servers.net.
.                       512780  IN      NS      a.root-servers.net.
.                       512780  IN      NS      h.root-servers.net.
.                       512780  IN      NS      j.root-servers.net.
.                       512780  IN      NS      d.root-servers.net.
.                       512780  IN      NS      c.root-servers.net.
.                       512780  IN      NS      i.root-servers.net.
;; Received 500 bytes from 127.0.0.1#53(127.0.0.1) in 0 ms

us.                     172800  IN      NS      I.GTLD.BIZ.
us.                     172800  IN      NS      J.GTLD.BIZ.
us.                     172800  IN      NS      K.GTLD.BIZ.
us.                     172800  IN      NS      B.GTLD.BIZ.
us.                     172800  IN      NS      A.GTLD.BIZ.
us.                     172800  IN      NS      C.GTLD.BIZ.
;; Received 308 bytes from 128.8.10.90#53(d.root-servers.net) in 48 ms

k12.ia.us.              7200    IN      NS      DNS-2.IASTATE.EDU.
k12.ia.us.              7200    IN      NS      DNS2.ICN.STATE.ia.us.
k12.ia.us.              7200    IN      NS      DNS3.UIOWA.EDU.
;; Received 141 bytes from 156.154.96.126#53(I.GTLD.BIZ) in 97 ms

sioux-center.k12.ia.us. 28800   IN      NS      ns1.netins.net.
sioux-center.k12.ia.us. 28800   IN      NS      dns.mtcnet.net.
;; Received 109 bytes from 128.255.64.5#53(DNS3.UIOWA.EDU) in 18 ms

sioux-center.k12.ia.us. 86400   IN      NS      ns2.mtcnet.net.
sioux-center.k12.ia.us. 86400   IN      NS      ns1.mtcnet.net.
sioux-center.k12.ia.us. 86400   IN      NS      ns1.netins.net.
;; Received 159 bytes from 167.142.225.5#53(ns1.netins.net) in 9 ms