Port 53 — DNS
Conventional DNS uses port 53 over UDP and TCP. Treating DNS as a UDP-only service can cause incomplete or intermittent resolution.
Registry assignments, software defaults and local listeners are different things. A port number alone does not identify or secure a service.
Configuration and troubleshooting
Inspect TCP and UDP listeners and firewall rules separately. If small queries work while others fail, test the TCP path too.
Important limitations
Restrict clients allowed to use a recursive resolver. Absence of a port-53 listener does not rule out encrypted DNS or another resolver path.
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 Using This Port (4 software)
Community software entries: links are references, not individual verification.
Usage Suggestions
- Before using port 53, please confirm it is not occupied by other services
- If you encounter port conflicts, consider using other ports or stopping the occupying service
Quick Info
- Port
- 53
- Protocol
- TCP/UDP
- Categories
- DNS Services
- Usage Status
- 4 software in use
Related Ports
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