Port 4138
nettest · TCP/UDP
| Range | Registered port (1024–49151) |
|---|---|
| Protocol | TCP/UDP |
| Service | nettest |
| Registered | 2003-03 |
Frequently asked questions
What is port 4138 used for?
Port 4138 is registered with the IANA for nettest (TCP/UDP). Description: nettest.
Is port 4138 a well-known port?
No. Port 4138 is in the range 1024–49151 (registered or user ports). Ordinary programs may open it without root privileges.
How do I check whether port 4138 is open?
Locally on Linux with ss -tulpn | grep ':4138\b', on Windows with netstat -ano | findstr :4138. To test a remote host use Test-NetConnection <host> -Port 4138 in PowerShell or nc -zv <host> 4138 on Linux/macOS.
How do I open port 4138 in the firewall?
Ubuntu/Debian (ufw): sudo ufw allow 4138/tcp. Fedora/RHEL (firewalld): sudo firewall-cmd --add-port=4138/tcp --permanent, then firewall-cmd --reload. Windows (PowerShell as administrator): New-NetFirewallRule -DisplayName "Port 4138" -Direction Inbound -Protocol TCP -LocalPort 4138 -Action Allow.
IANA registry entries
| Protocol | Service | Description (IANA) |
|---|---|---|
| TCP | nettest | nettest |
| UDP | nettest | nettest |