dns4.sol.net has no CNAME records.
Question and response
Question
dig dns4.sol.net. NS
Answer
The response has no answer records.
Authority
sol.net. 10430 SOA dns1.sol.net. hostmaster.ns.sol.net. 2024060601 86400 14400 604800 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0