poplink.jp.		30 IN SOA ns-a1.conoha.io. postmaster.example.org. (
				1755581004 ; serial
				3600       ; refresh (1 hour)
				600        ; retry (10 minutes)
				86400      ; expire (1 day)
				3600       ; minimum (1 hour)
				)

Name servers:
poplink.jp.		30 IN NS ns-a2.conoha.io.
poplink.jp.		30 IN NS ns-a1.conoha.io.
poplink.jp.		30 IN NS ns-a3.conoha.io.