Servidores DNS Principal (mname) y Secundario (rname)
host: claroapps.com
class: IN
ttl: 3600
type: SOA
mname: ns.rackspace.com
rname: hostmaster.rackspace.com
serial: 1572634891
refresh: 3600
retry: 300
expire: 1814400
minimum-ttl: 300