Protection for Lame Delegation (Dangling NS records)

a cat of MLIT 
   tochi30.mlit.go.jp.	86400 IN NS ns1.dns.ne.jp.
   tochi30.mlit.go.jp.	86400 IN NS ns2.dns.ne.jp.

from Jan 12 15:10 by tss @ suzuki.sist.chukyo-u.ac.jp