Authority delegation (2)

Specified by an NS RR in the parent zone
    wide.ad.jp. 1D IN NS ns-wide.ad.jp.
Glue RR
provide IP address(es) of the name server specified by NS
typically A/AAAA RRs
stored in the upper (parent) zone
without a glue, client could not get access to the child zone
    ns-wide.wide.ad.jp. 1D IN A 203.178.136.36