dns2.oktawave.com has no CNAME records.
Question and response
Question
dig dns2.oktawave.com. NS
Answer
The response has no answer records.
Authority
oktawave.com. 10800 SOA ns1.oktawave.com. hostmaster.oktawave.com. 2025111700 28800 7200 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0