Network / Port Check Tools

RaceLab communicates with your sims and other software through network ports. If overlays are not connecting or telemetry data is missing, it’s often worth checking which ports are open and which app is using them.

On Windows 11 the easiest and most reliable way to do this is with Resource Monitor — no command line needed. It’s built into Windows and shows all listening ports in a clear list.

Open the Start menu and type Resource Monitor.
Go to the Network tab.
Expand Listening Ports to see every program using a network port.
Look for RaceLab.exe or your sim’s executable name and note the port numbers in use.

This makes it simple to confirm whether telemetry ports (for example 8080, 8182 or 9000 depending on the sim) are open and not being blocked by another app or firewall rule.

You can still use netstat -a or netstat -b in a command prompt for the same data, but Resource Monitor is far easier to read and updates live while RaceLab is running.

Checking ports and connections

Using Resource Monitor (Windows built-in)

Press Windows + R, type resmon and press Enter.
Go to the Network tab.
Expand Listening Ports to view all open network ports.
Look for entries related to RaceLab.exe or your sim (e.g. iRacingSim64DX11.exe).
Confirm that RaceLab or the sim is listening on the correct port (for example 8080 for RaceLab’s local overlay server).

If another program is already using that same port, RaceLab may not start or overlays will fail to load. Closing the conflicting app or changing the port in RaceLab settings usually resolves it.

Other quick-check methods

Command Prompt > netstat -ano
Shows all open ports and the process ID (PID). Combine it with tasklist | find "PID" to identify which app owns the port.
PowerShell > Get-NetTCPConnection
Modern alternative that lists ports and processes in table format.
TCPView (by Sysinternals)
Free Microsoft tool showing live network connections with process names, ports and states. Download from Microsoft Sysinternals – TCPView .
Firewall check
If RaceLab still cannot connect, temporarily disable Windows Defender Firewall (or add an allow rule for RaceLab.exe) to test if the port is being blocked.

Tip: RaceLab’s local web server should normally show Listening on http://localhost:8080 in the console window when running correctly. If you don’t see that line, something else may already be using the port.