Port 9123
grcp · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | grcp |
| Registered | 2012-11-28 |
| Modified | 2025-06-12 |
Frequently asked questions
What is port 9123 used for?
Port 9123 is registered with the IANA for grcp (TCP/UDP). Description: Global Relay compliant instant messaging protocol; Reserved.
Is port 9123 a well-known port?
No. Port 9123 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 9123 is open?
Locally on Linux with ss -tulpn | grep ':9123\b', on Windows with netstat -ano | findstr :9123. To test a remote host use Test-NetConnection <host> -Port 9123 in PowerShell or nc -zv <host> 9123 on Linux/macOS.
How do I open port 9123 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 9123/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=9123/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 9123" -Direction Inbound -Protocol TCP -LocalPort 9123 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | grcp | Global Relay compliant instant messaging protocol |
| UDP | – | Reserved |