mx1.FROMDOMRU.RU has no NS records.
NS records for this zone are defined at FROMDOMRU.RU.
NS records for this zone are defined at FROMDOMRU.RU.
Question and response
Question
dig mx1.FROMDOMRU.RU. NS
Answer
The response has no answer records.
Authority
fromdomru.ru. 3600 SOA ns8.ertelecom.ru. noc.ertelecom.ru. 2022120200 28800 7200 604800 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0