$TTL 1D
@ IN SOA x.dns.jp. root.jp. (
  2024090801    ; serial
          1D    ; refresh
          1H    ; retry
          1W    ; expire
     2000000 )  ; minimum

jp.                 3600 IN NS   x.dns.jp.
jp.                 3600 IN NS   y.dns.jp.
jp.                 3600 IN NS   z.dns.jp.
x.dns.jp.           3600 IN A    172.18.1.8
y.dns.jp.           3600 IN A    172.18.1.9
z.dns.jp.           3600 IN A    172.18.1.10
x.dns.jp.           3600 IN AAAA fd00::8
y.dns.jp.           3600 IN AAAA fd00::9
z.dns.jp.           3600 IN AAAA fd00::a

test.co             3600 IN NS   ns1.test.jp.
test.co             3600 IN NS   ns2.test.jp.
ns1.test.jp.        3600 IN A    172.18.1.16
ns2.test.jp.        3600 IN A    172.18.1.17