.                   518400 IN NS   x.root-servers.net.
.                   518400 IN NS   y.root-servers.net.
.                   518400 IN NS   z.root-servers.net.
x.root-servers.net. 518400 IN A    172.18.1.4
y.root-servers.net. 518400 IN A    172.18.1.5
z.root-servers.net. 518400 IN A    172.18.1.6
x.root-servers.net. 518400 IN AAAA fd00::4
y.root-servers.net. 518400 IN AAAA fd00::5
z.root-servers.net. 518400 IN AAAA fd00::6