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Electronic Theatre Controls Inc

Troubleshooting Net3 Discovery

On Windows computers, Net3 products (including Consoles, Gateway Configuration Editor, and Concert) all use a background service called "SLP" (Service Location Protocol) to discover other devices on the network.

A variety of problems can cause SLP to be unable to discover devices, which will appear as devices not showing up in the software you are using. Some troubleshooting possibilities are shown here.

HP Printer Driver Software Blocking SLP

Some HP printer driver software may block the network port required for SLP to run, leading it to appear not to work. You can disable the HP printer software in question by:

  1. Hold the Windows key and press R, then type services.msc to open the services control panel
    Services Control Panel
  2. Scroll down and look for a service called "HP Network Devices Support
    HP Network Devices Support
  3. Double click on the service, and change the Startup type to Disabled, and press Stop to stop the service.
  4. Press OK, and restart the ETC application you are trying to use. You should now be able to connect.
Note : You will need to re-enable the service to discover HP printers.

Other Software Blocking SLP

ETC Technical Services has seen a few other manufacturers using some proprietary SLP implementations that don't seem to share their discovery data with other applications. 

These situations are always a bit of an adventure -- spelunking through the system to discover the program grabbing the SLP network port and denying access to Net3 applications.

Microsoft Sysinternals has a software program called TCPView that shows what processes are using what network ports.  If you run that program and look for things using port 427, you'll likely find the culprit.  If it is a service, you can follow steps like described above to stop and disable the offender.  If it is an individual runtime application, close it via whatever programmatic mechanism is appropriate.

Additional services to be aware of that can block SLP include Brother and Epson network printer services.

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