Comtrend PG-9172 configuration

This procedure assumes you already have two or more encrypted Comtrend powerline Ethernet units working on profile “PLC 50MHz with MIMO”, and you’re adding another. You can do this on any operating system with an Ethernet adapter and web browser.

  1. setup your PC Ethernet adapter (temporarily) to static IP of, subnet You do not need gateway or DNS.
  2. browse to factory default IP address in your web browser: Default password is admin
  3. keep this browser window open, and open a second window.
  4. unplug this new unit, and connect laptop to primary unit via Ethernet.
  5. browse to the primary IP address (perhaps and click Pair. This makes the primary ready to accept new units
  6. Plug in via Ethernet to the new and click Pair. It will promptly make you login again, click Pair and refresh. You should see the same random “domain name”, “pairing password” and “Domain ID DOD” as the primary.
  7. Plug in the primary Ethernet back to the network as it was before. You should see the middle green light go back on.
  8. On the new unit, the top and bottom green lights should be steady green, with the middle light flickering with Ethernet activity.
  9. Put your PC Ethernet back to its previous configuration (probably DHCP). You should be able to browse the web over the new connection after resetting your Ethernet adapter (or unplug/plug).


  • be sure your primary unit (the one connected to the actual hardwired Ethernet Internet connection) has node type DOMAIN_MASTER
  • be sure all other units node type are END_POINT.
  • be sure you’re not using power strips or surge suppressors on the power outlets. The only way they’ll work is directly into a wall outlet (GFCI is OK).
  • Only use profile “PLC 50MHz with MIMO” as this gives maximum range with multiple breaker panels in large houses, since it uses all three powerline wires.
  • NDIM mode should be automatic; after pairing it will be on the same Domain ID DOD.
  • You should use encryption or someone can just plug into an outlet on the outside (or inside) of your house and hack away at your network.
  • consider setting each device to a unique IPv4 manual address. Then, when you plug directly into one of them, you can use your web browser to see your other adapter config pages.
  • The manually set IPv4 should NOT be on the same subnet as your network. For some reason, it just won’t work.

Upgrading firmware:

At the time of writing, it must be a Windows 7 PC as newer Windows versions are not supported yet. You’ll just get errors if not on Windows 7. A virtual machine of Windows 7 did not work, it had to be a bare metal Windows 7 installation. You have to install Java as well.

You might have to try once or twice, try resetting power to the PG-9172. Try resetting to factory defaults too. It should work to upgrade firmware after 1-2 tries.

You cannot do this remotely, you have to be directly plugged into the Ethernet jack of the PG-9172 from your Windows 7 PC to upgrade Comtrend PG-9172 firmware.