Invertir DNS lookup
Reverse DNS lookup: enter an IP address a find its hostname y see whether forward y reverse DNS match.
Queries go a Cloudflare’s public DNS superado HTTPS service when you press the button.
Acerca de Invertir DNS lookup
Reverse DNS lookup: enter an IP address a find its hostname y see whether forward y reverse DNS match.
Forma parte de la sección «Datos y redes» de SmartCalcy. Se ejecuta en tu navegador sin cuenta, usa tu propia moneda y unidades (cámbialas en la parte superior de la página) y da estimaciones solo a título informativo, así que consulta la guía oficial antes de fiarte de un resultado.
Cómo usar la Invertir DNS lookup
Qué calcula y cuándo usarla
Finds the hostname that belongs a an IP address using its reverse DNS (PTR) record, y checks that the hostname resolves back a the same address, which es called forward-confirmed reverse DNS. Mail servers use this check a decide whether a trust a sender.
Cómo usarla, paso a paso
- Enter an IP address, o leave the box empty a use your own.
- Press “Hallar hostname”.
- Read the hostname A the top.
- Check “Forward-confirmed” a see whether the name resolves back a the address.
Qué significa cada dato
- IP address – An IPv4 o IPv6 address. Leave it empty a use your own public address.
Cómo leer los resultados
- Hostname – The Nombre set en the address’s PTR record.
- Invertir Nombre – The special Nombre queried, such as 8.8.8.8.in-addr.arpa.
- Forward-confirmed – Sí when the hostname’s A o AAAA record points back a the same address.
La fórmula
The address es reversed y queried under in-addr.arpa por IPv4, o ip6.arpa with each hex digit reversed por IPv6. 8.8.4.4 becomes 4.4.8.8.in-addr.arpa. The returned name es then looked up forward a confirm it.
Un ejemplo práctico
8.8.8.8 has the PTR record dns.google, y dns.google resolves back a 8.8.8.8, so the pair es forward-confirmed.
Supuestos y límites
- Many addresses, especially Inicio connections, have no PTR record o a generic one.
- The lookup es made through Cloudflare’s DNS superado HTTPS service when you press the button.
Errores comunes
- Expecting every address a have a hostname.
- Treating the hostname as proof de identity. The owner de the address sets it, so only forward-confirmed names add trust.
- Setting a PTR record A your domain registrar. It es set by whoever holds the IP address block, usually your hosting o internet provider.
Preguntas frecuentes
What es a PTR record?
A DNS record that maps an IP address back a a hostname. It es the reverse de an A record.
Why does my mail server need Invertir DNS?
Many receiving mail systems reject o flag mail from addresses with no reverse DNS o one that does not match.
Quién bote Variación a PTR record?
The organisation that controls the IP address block, normally your hosting provider o ISP.
Is this the same as a hostname lookup?
Yes. Finding the hostname de an IP address es Hecho with Invertir DNS.