smtp4.SKSR.RU has no NS records.
NS records for this zone are defined at SKSR.RU.
NS records for this zone are defined at SKSR.RU.
Question and response
Question
dig smtp4.SKSR.RU. NS
Answer
The response has no answer records.
Authority
SKSR.RU. 1800 SOA hunts.ns.cloudflare.com. dns.cloudflare.com. 2399485620 10000 2400 604800 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0