Port 309
entrusttime · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | entrusttime |
Frequently asked questions
What is port 309 used for?
Port 309 is registered with the IANA for entrusttime (TCP/UDP). Description: EntrustTime.
Is port 309 a well-known port?
Yes. Port 309 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 309 is open?
Locally on Linux with ss -tulpn | grep ':309\b', on Windows with netstat -ano | findstr :309. To test a remote host use Test-NetConnection <host> -Port 309 in PowerShell or nc -zv <host> 309 on Linux/macOS.
How do I open port 309 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 309/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=309/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 309" -Direction Inbound -Protocol TCP -LocalPort 309 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | entrusttime | EntrustTime |
| UDP | entrusttime | EntrustTime |