Port 3255

semaphore · TCP/UDP

RangeRegistered port (1024–49151)
ProtocolTCP/UDP
Servicesemaphore
Registered2002-02

Frequently asked questions

What is port 3255 used for?

Port 3255 is registered with the IANA for semaphore (TCP/UDP). Description: Semaphore Connection Port.

Is port 3255 a well-known port?

No. Port 3255 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.

How do I check whether port 3255 is open?

Locally on Linux with ss -tulpn | grep ':3255\b', on Windows with netstat -ano | findstr :3255. To test a remote host use Test-NetConnection <host> -Port 3255 in PowerShell or nc -zv <host> 3255 on Linux/macOS.

How do I open port 3255 in the firewall?

Ubuntu/Debian (ufw): sudo ufw allow 3255/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=3255/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 3255" -Direction Inbound -Protocol TCP -LocalPort 3255 -Action Allow.

IANA registry entries

ProtocolServiceDescription (IANA)
TCPsemaphoreSemaphore Connection Port
UDPsemaphoreSemaphore Connection Port

Nearby entries