Puerto53— DNS
DNS convencional usa el puerto 53 tanto por UDP como por TCP. Tratarlo como un servicio exclusivo de UDP puede provocar una resolución incompleta o intermitente.
Registry assignments, software defaults and local listeners are different things. A port number alone does not identify or secure a service.
Configuration and troubleshooting
Revise por separado los sockets de escucha y las reglas del cortafuegos de TCP y UDP. Si las consultas pequeñas funcionan y otras fallan, pruebe también la ruta TCP.
Important limitations
Restrinja los clientes autorizados a usar un resolvedor recursivo. La ausencia de un socket en escucha en el puerto 53 no descarta DNS cifrado u otra vía de resolución.
Read-only checks: run on the server host
Choose the commands for your OS. Check TCP and UDP separately. No result is not a lasting availability guarantee; inspect host and container separately.
Linux
sudo ss -ltnp 'sport = :53'
sudo ss -lunp 'sport = :53'macOS
sudo lsof -nP -iTCP:53 -sTCP:LISTEN
sudo lsof -nP -iUDP:53Windows PowerShell
Get-NetTCPConnection -LocalPort 53 -State Listen
Get-NetUDPEndpoint -LocalPort 53Sources and review
Sources checked on:
This review covers the explanations and sources on this page, not your device or every community software entry below.
Related troubleshooting guides
Software que utiliza este puerto (4 programas)
Community software entries: links are references, not individual verification.
Recomendaciones de uso
- Antes de utilizar el puerto 53, comprueba que no esté ocupado por otros servicios
- Si encuentras conflictos de puertos, considera utilizar otros puertos o detener el servicio que lo ocupa
Preguntas frecuentes
What is port 53 used for?
Port 53 sits in the DNS Services category. This page lists the registered purpose and the software commonly associated with it; to see what is actually listening on a specific machine, check the process with ss/netstat.
Is port 53 TCP or UDP?
The registered protocol on this page is TCP / UDP. The same number behaves independently on each protocol: TCP may be listening while UDP is idle, so check them separately.
How do I check if port 53 is in use?
On Linux: sudo ss -tlnp 'sport = :53' for an exact port match. On macOS: sudo lsof -nP -iTCP:53 -sTCP:LISTEN. On Windows PowerShell: Get-NetTCPConnection -LocalPort 53 -State Listen. A listener counts as confirmed only when you can see the bind address and process name; without root/admin you will not see other users' processes.
Is port 53 secure? Should I open it in my firewall?
A port number has no inherent security — it depends on whether the listening service is correctly configured and whether it needs exposure at all. Keep loopback/internal-only services firewalled; where public access is required, pair it with source restrictions, VPN or authentication. The caution section on this page lists port-specific risks.
Información rápida
- Puerto
- 53
- Protocolo
- TCP/UDP
- Categorías
- Servicios DNS
- Estado de uso
- 4 programas que lo utilizan
Puertos relacionados
¿Necesitas ayuda?
Si encuentras información incorrecta o necesitas añadir más, envíanos una corrección.
Enviar una corrección