Port 656
spmp · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | spmp |
Frequently asked questions
What is port 656 used for?
Port 656 is registered with the IANA for spmp (TCP/UDP). Description: SPMP.
Is port 656 a well-known port?
Yes. Port 656 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 656 is open?
Locally on Linux with ss -tulpn | grep ':656\b', on Windows with netstat -ano | findstr :656. To test a remote host use Test-NetConnection <host> -Port 656 in PowerShell or nc -zv <host> 656 on Linux/macOS.
How do I open port 656 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 656/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=656/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 656" -Direction Inbound -Protocol TCP -LocalPort 656 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | spmp | SPMP |
| UDP | spmp | SPMP |