ns2.SWEB.RU has no CNAME records.
Question and response
Question
dig ns2.SWEB.RU. NS
Answer
The response has no answer records.
Authority
SWEB.RU. 300 SOA ns1.SWEB.RU. postmaster.SWEB.RU. 2023050904 7200 3600 14400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0