Protection for Lame Delegation (Dangling NS records)

a cat of MLIT 
   productivity-innovation.mlit.go.jp. 300	IN NS	ns1.dns.ne.jp.
   productivity-innovation.mlit.go.jp. 300	IN NS	ns2.dns.ne.jp.

from Jan 12 16:20 by tss @ suzuki.sist.chukyo-u.ac.jp