Servidores DNS Principal (mname) y Secundario (rname)
host: 17bc.com
class: IN
ttl: 3877
type: SOA
mname: ns1.namebrightdns.com
rname: dns.namebright.com
serial: 2026052501
refresh: 28800
retry: 5000
expire: 1209600
minimum-ttl: 10800