Servidores DNS Principal (mname) y Secundario (rname)
host: big-h.biz
class: IN
ttl: 3600
type: SOA
mname: ns1-03.azure-dns.com
rname: azuredns-hostmaster.microsoft.com
serial: 1
refresh: 3600
retry: 300
expire: 2419200
minimum-ttl: 300