Quick diagnostics—is the device reachable?

Before diving into configuration, run two quick tests to determine whether the problem is hardware (the DragonFly is not reachable at all) or software (the device is reachable but the communication protocol is failing).

Test 1—Open the web interface

Open a browser on the observatory PC and go to:

http://dragonfly

If the DragonFly's built-in web page loads, the device is on the network and the hostname is resolving correctly. The problem is in the software communication layer; continue to the UDP port section below.

Test 2—Ping the device

Open a command prompt and run a continuous ping:

ping -t dragonfly

If the ping replies, the device is reachable. If it times out, the device is not being found on the network: check the physical connection (Ethernet cable, switch/router port) and try a different router port.

UDP port conflicts—the most common cause

The DragonFly communicates over UDP on port 10000 by default. This is a well-known source of trouble in observatory setups because several popular devices also use port 10000, most notably IP cameras from Foscam, Dahua and similar brands.

The symptom is intermittent disconnections or a failure to receive data even though the device appears connected. This happens because the camera is answering on the same port, so the DragonFly packets are being misrouted.

Network SQM (Sky Quality Meter) devices often use port 10001, which can cause the same issue if you have switched to that port as a workaround in the past.

How to fix port conflicts

  1. Open the DragonFly's web interface (http://dragonfly) and navigate to network settings.
  2. Change the Listen port to a higher, unused number. Port 10101 has proved reliable in practice, as it avoids the camera and SQM ranges.
  3. In the DragonFly software on the PC, set the client port to 0. This tells the software to let the OS select an available outgoing port automatically, avoiding conflicts on the PC side too.
  4. Save the settings and reconnect.

Tip: if you are not sure which devices on your network are using which ports, a free tool such as CurrPorts (Windows) will show all active UDP listeners. Look for anything on port 10000 before making the change.

Device not reachable—network discovery

If the ping and browser tests both fail, the DragonFly is not being found on the network at all. Common causes:

  • Physical connection: check that the Ethernet cable is seated and the link LED on the DragonFly port is lit. Try a different cable or a different port on the switch/router.
  • Hostname not resolving: try accessing the device by IP address directly instead of the hostname. Find the IP from your router's DHCP client list or with a network scanner (Advanced IP Scanner, Angry IP Scanner).
  • Windows network discovery: recent Windows 10 and 11 security updates can prevent simple devices from being visible. See the network accessibility guide for the hosts-file fix.

Still not connecting?

If none of the above resolves the issue, try a factory reset. This restores the DragonFly to DHCP mode with the default hostname. See the factory network reset guide.

For persistent problems, contact the support team via the Lunatico support portal with your firmware version and network setup details.