Servidores DNS Principal (mname) y Secundario (rname)
host: isohair.us
class: IN
ttl: 6573
type: SOA
mname: udns1.cscdns.net
rname: hostmaster.cscdns.net
serial: 2021030801
refresh: 86400
retry: 86400
expire: 86400
minimum-ttl: 86400