$TTL 300        ; 5 minutes
@                       IN SOA  ns root (
				2018010100 ; serial
				1800       ; refresh (30 minutes)
				1800       ; retry (30 minutes)
				1814400    ; expire (3 weeks)
				3600       ; minimum (1 hour)
				)
			NS      ns
ns                      A       10.53.0.1
server			A	10.53.0.100
child			NS	ns.child
ns.child		A	10.53.0.1