Servidores DNS Principal (mname) y Secundario (rname)
host: gruppodarco.coop
class: IN
ttl: 21600
type: SOA
mname: ns1.open-desk.it
rname: postmaster.ns1.open-desk.it
serial: 2018030100
refresh: 28800
retry: 7200
expire: 604800
minimum-ttl: 86400