idaxue.cn.		599 IN SOA ns6.dnsdun.com. ns6.dnsdun.com. (
				1          ; serial
				3600       ; refresh (1 hour)
				180        ; retry (3 minutes)
				1209600    ; expire (2 weeks)
				180        ; minimum (3 minutes)
				)

Name servers:
idaxue.cn.		3599 IN	NS ns6.dnsdun.net.
idaxue.cn.		3599 IN	NS ns6.dnsdun.com.