ftpbackup-01.cco.singlehop.net has no NS records.
NS records for this zone are defined at singlehop.net.
NS records for this zone are defined at singlehop.net.
Question and response
Question
dig ftpbackup-01.cco.singlehop.net. NS
Answer
The response has no answer records.
Authority
singlehop.net. 3600 SOA ns1.singlehop.com. netops.singlehop.com. 2012060503 86400 7200 3600000 86400
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0