Servidores DNS Principal (mname) y Secundario (rname)
host: ecog.org
class: IN
ttl: 300
type: SOA
mname: a1-171.akam.net
rname: netmanager.harvard.edu
serial: 2023062003
refresh: 10800
retry: 3600
expire: 2419200
minimum-ttl: 3600