Servidores DNS Principal (mname) y Secundario (rname)
host: realtimepub.com
class: IN
ttl: 3600
type: SOA
mname: pns1.cloudns.net
rname: support.cloudns.net
serial: 2026062621
refresh: 7200
retry: 1800
expire: 1209600
minimum-ttl: 3600