Port 533
netwall · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | netwall |
Frequently asked questions
What is port 533 used for?
Port 533 is registered with the IANA for netwall (TCP/UDP). Description: for emergency broadcasts.
Is port 533 a well-known port?
Yes. Port 533 is in the range 0–1023 (system or well-known ports). On Linux and macOS only privileged processes may bind to these ports.
How do I check whether port 533 is open?
Locally on Linux with ss -tulpn | grep ':533\b', on Windows with netstat -ano | findstr :533. To test a remote host use Test-NetConnection <host> -Port 533 in PowerShell or nc -zv <host> 533 on Linux/macOS.
How do I open port 533 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 533/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=533/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 533" -Direction Inbound -Protocol TCP -LocalPort 533 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | netwall | for emergency broadcasts |
| UDP | netwall | for emergency broadcasts |