Port 428
ocs-cmu and ocs_cmu · TCP/UDP
| Range | System/well-known port (0–1023) |
|---|---|
| Protocol | TCP/UDP |
| Service | ocs-cmu and ocs_cmu |
Frequently asked questions
What is port 428 used for?
Port 428 is registered with the IANA for ocs-cmu and ocs_cmu (TCP/UDP). Description: OCS_CMU IANA assigned this well-formed service name as a replacement for "ocs_cmu".; OCS_CMU.
Is port 428 a well-known port?
Yes. Port 428 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 428 is open?
Locally on Linux with ss -tulpn | grep ':428\b', on Windows with netstat -ano | findstr :428. To test a remote host use Test-NetConnection <host> -Port 428 in PowerShell or nc -zv <host> 428 on Linux/macOS.
How do I open port 428 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 428/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=428/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 428" -Direction Inbound -Protocol TCP -LocalPort 428 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | ocs-cmu | OCS_CMU IANA assigned this well-formed service name as a replacement for "ocs_cmu". |
| TCP | ocs_cmu | OCS_CMU |
| UDP | ocs-cmu | OCS_CMU IANA assigned this well-formed service name as a replacement for "ocs_cmu". |
| UDP | ocs_cmu | OCS_CMU |