r01.sfldmi01.washftth.com has no NS records.
NS records for this zone are defined at washftth.com.
NS records for this zone are defined at washftth.com.
Question and response
Question
dig r01.sfldmi01.washftth.com. NS
Answer
The response has no answer records.
Authority
washftth.com. 3601 SOA dns1.registrar-servers.com. hostmaster.registrar-servers.com. 1773631679 43200 3600 604800 3601
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0