Servidores DNS Principal (mname) y Secundario (rname)
host: appsto.re
class: IN
ttl: 600
type: SOA
mname: ns-ext-prod.jackfruit.edge.apple.com
rname: dnscontact.apple.com
serial: 3
refresh: 3600
retry: 2700
expire: 604800
minimum-ttl: 300