esxi-3.fra15.fra.GBlNET.net has no CNAME records.
Question and response
Question
dig esxi-3.fra15.fra.GBlNET.net. NS
Answer
The response has no answer records.
Authority
fra.GBlNET.net. 4157 SOA ns.GBlNET.net. vvv.GBlNET.net. 2025070701 10800 1200 1209600 259200
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0