sdtc.ar01.fa1-78.network.23570.americanis.net has no NS records.
NS records for this zone are defined at americanis.net.
NS records for this zone are defined at americanis.net.
Question and response
Question
dig sdtc.ar01.fa1-78.network.23570.americanis.net. NS
Answer
The response has no answer records.
Authority
americanis.net. 300 SOA ns1.americanis.net. root.ns1.americanis.net. 2648872907 10800 900 432000 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0