Servidores DNS Principal (mname) y Secundario (rname)
host: c500.com.cn
class: IN
ttl: 500
type: SOA
mname: ns1.myhostadmin.net
rname: dnsconct.myhostadmin.net
serial: 2018090411
refresh: 43200
retry: 300
expire: 1209600
minimum-ttl: 3600