Servidores DNS Principal (mname) y Secundario (rname)
host: air-quality-group.com
class: IN
ttl: 18343
type: SOA
mname: ns20.digicertdns.com
rname: dns.digicertdns.com
serial: 2009010101
refresh: 43200
retry: 3600
expire: 1209600
minimum-ttl: 180