Port 56
xns-auth · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | xns-auth |
Frequently asked questions
What is port 56 used for?
Port 56 is registered with the IANA for xns-auth (TCP/UDP). Description: XNS Authentication.
Is port 56 a well-known port?
Yes. Port 56 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 56 is open?
Locally on Linux with ss -tulpn | grep ':56\b', on Windows with netstat -ano | findstr :56. To test a remote host use Test-NetConnection <host> -Port 56 in PowerShell or nc -zv <host> 56 on Linux/macOS.
How do I open port 56 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 56/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=56/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 56" -Direction Inbound -Protocol TCP -LocalPort 56 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | xns-auth | XNS Authentication |
| UDP | xns-auth | XNS Authentication |