dns2.tankbar.com has no CNAME records.
Question and response
Question
dig dns2.tankbar.com. NS
Answer
The response has no answer records.
Authority
tankbar.com. 3600 SOA tankbar.com. hostmaster.tankbar.com. 2005043085 28800 7200 604800 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0