55.0-255.219.51.204.in-addr.arpa has no NS records.
NS records for this zone are defined at 219.51.204.in-addr.arpa.
NS records for this zone are defined at 219.51.204.in-addr.arpa.
Question and response
Question
dig 55.0-255.219.51.204.in-addr.arpa. NS
Answer
The response has no answer records.
Authority
219.51.204.in-addr.arpa. 300 SOA ns.rackspace.com. hostmaster.rackspace.com. 1539015529 3600 300 1814400 300
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0