208.128.57.160.210.in-addr.arpa has no NS records.
NS records for this zone are defined at 128.57.160.210.in-addr.arpa.
NS records for this zone are defined at 128.57.160.210.in-addr.arpa.
Question and response
Question
dig 208.128.57.160.210.in-addr.arpa. NS
Answer
The response has no answer records.
Authority
128.57.160.210.in-addr.arpa. 900 SOA os12-dnsic1-dns1.anser.ne.jp. please_set_email.absolutely.nowhere. 2016071854 10800 3600 2592000 900
Additional
. 0 OPT ; payload 1220, xrcode 0, version 0, flags 0