Servidores DNS Principal (mname) y Secundario (rname)
host: thursday-13.com
class: IN
ttl: 497
type: SOA
mname: dns1.registrar-servers.com
rname: hostmaster.registrar-servers.com
serial: 1771945678
refresh: 43200
retry: 3600
expire: 604800
minimum-ttl: 3601