mx.vip.corp.gslb.kcom.com has no NS records.
NS records for this zone are defined at gslb.kcom.com.
NS records for this zone are defined at gslb.kcom.com.
Question and response
Question
dig mx.vip.corp.gslb.kcom.com. NS
Answer
The response has no answer records.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0