Para saber las DNS de un domino debemos de escribir en nuestra terminal:
host dominio.com
Esto nos devolverá las DNS a las que apunta este domino.
Por ejemplo, para ver las DNS de Twitter deberíamos teclear:
host twitter.com
Nos da como resultado:
twitter.com has address 104.244.42.193 twitter.com has address 104.244.42.129 twitter.com mail is handled by 20 alt2.aspmx.l.google.com. twitter.com mail is handled by 10 aspmx.l.google.com. twitter.com mail is handled by 30 ASPMX3.GOOGLEMAIL.com. twitter.com mail is handled by 20 alt1.aspmx.l.google.com. twitter.com mail is handled by 30 ASPMX2.GOOGLEMAIL.com.
Con -t NS filtramos para que solo nos muestre los NAME SERVERS:
host -t NS twitter.com
Nos devolvería:
twitter.com name server ns1.p34.dynect.net. twitter.com name server ns2.p34.dynect.net. twitter.com name server ns4.p34.dynect.net. twitter.com name server ns3.p34.dynect.net.
Si en en cambio, queremos una información más extensa podemos añadirle el parámetro -a.
host -a twitter.com
Que nos respondería:
Trying "twitter.com" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 37822 ;; flags: qr rd ra; QUERY: 1, ANSWER: 8, AUTHORITY: 0, ADDITIONAL: 4 ;; QUESTION SECTION: ;twitter.com. IN ANY ;; ANSWER SECTION: twitter.com. 281 IN TXT "google-site-verification=h6dJIv0HXjLOkGAotLAWEzvoi9SxqP4vjpx98vrCvvQ" twitter.com. 281 IN TXT "v=spf1 ip4:199.16.156.0/22 ip4:199.59.148.0/22 ip4:8.25.194.0/23 ip4:8.25.196.0/23 ip4:204.92.114.203 ip4:204.92.114.204/31 ip4:23.21.83.90 include:_spf.google.com include:_thirdparty.twitter.com -all" twitter.com. 84427 IN NS ns4.p34.dynect.net. twitter.com. 84427 IN NS ns3.p34.dynect.net. twitter.com. 84427 IN NS ns1.p34.dynect.net. twitter.com. 84427 IN NS ns2.p34.dynect.net. twitter.com. 56 IN A 104.244.42.1 twitter.com. 56 IN A 104.244.42.193 ;; ADDITIONAL SECTION: ns1.p34.dynect.net. 40188 IN A 208.78.70.34 ns2.p34.dynect.net. 40127 IN A 204.13.250.34 ns4.p34.dynect.net. 40093 IN A 204.13.251.34 ns3.p34.dynect.net. 39227 IN A 208.78.71.34 Received 505 bytes from 62.81.16.164#53 in 10 ms