ns0.concur.net has no CNAME records.
Question and response
Question
dig ns0.concur.net. NS
Answer
The response has no answer records.
Authority
concur.net. 10800 SOA dns1.cscdns.net. hostmaster.cscdns.net. 2013021308 28800 7200 604800 14400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0