Servidores DNS Principal (mname) y Secundario (rname)
host: nlmgiftshop.info
class: IN
ttl: 1800
type: SOA
mname: gslb01.nlm.nih.gov
rname: hostmaster.gslb01.nlm.nih.gov
serial: 2021102001
refresh: 10800
retry: 3600
expire: 604800
minimum-ttl: 86400