Servidores DNS Principal (mname) y Secundario (rname)
host: panda-express.com
class: IN
ttl: 3600
type: SOA
mname: ns1.lexsynergy.net
rname: dnsmaster.lexsynergy.com
serial: 1
refresh: 302400
retry: 3600
expire: 1209600
minimum-ttl: 600