Registro IPv4
host: 21js.com
class: IN
ttl: 1800
type: A
ip: 221.12.138.143

Servidores DNS Principal (mname) y Secundario (rname)
host: 21js.com
class: IN
ttl: 3600
type: SOA
mname: 
rname: hostmaster.nameserver
serial: 451
refresh: 21600
retry: 1800
expire: 604800
minimum-ttl: 5