51host.net.		3600 IN	SOA kns3.51.net. root.kns3.51.net. (
				2001597050 ; serial
				21600      ; refresh (6 hours)
				7200       ; retry (2 hours)
				604800     ; expire (1 week)
				3600       ; minimum (1 hour)
				)

Mail exchangers:
51host.net.		3600 IN	MX 20 mx1.51host.net.
51host.net.		3600 IN	MX 10 mx2.51host.net.

Name servers:
51host.net.		3600 IN	NS kns3.51.net.
51host.net.		3600 IN	NS kns4.51.net.