dns6.NIPR.MIL has no CNAME records.
Question and response
Question
dig dns6.NIPR.MIL. NS
Answer
The response has no answer records.
Authority
NIPR.MIL. 2626 SOA dns1.NIPR.MIL. hostmaster\@nic.MIL. 37615 21600 3600 2419200 3600
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0