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How does the device discovery work?

Issue
In Smart Panel devices discovery, there are some asked questions because of a general misunderstanding of the discovery process.
 
The behavior looks different depending on the device (IFE, Com’X or SLIP) or on the used software (Ecoreach or Windows explorer)
 
For instance, on Windows explorer, a device can show up with its IP V4 or with its IP V6 address. It looks that the mechanism is not deterministic and sometimes you'll get the V4 and sometimes the V6.
 
Also, sometimes, devices are discovered within Windows Explorer, but not using Ecoreach.
 
Environment
Smart Panel and Windows Explorer / Smart Panel and Ecoreach
 
Cause
Windows explorer and Ecoreach use WS-Discovery protocol to find the connected devices.
 
Web Services Dynamic Discovery (WS-Discovery) is a technical specification that defines a multicast discovery protocol to locate services on a local network. It operates over UDP port 3702 and uses IP multicast address 239.255.255.250 (IPV4) or FF02::C (IPV6).
 
To discover the network, windows explorer sends discovery multicast messages in both IPV4 and IPV6 formats. Then the devices must answer with a random timer. If the device can answer to both format (IFE and COM’X default case, Smart Link IP if IPV6 enabled), it looks that Windows explorer keeps the first format of the IP address received and then will show it depending on this. Also, as the answer of this multicast discovery message is a unicast response, depending on the IPV4 subnet configured on the device, it might be possible that only the IPV6 answers will reach the requester.
 
Since Ecoreach sends discovery messages in IPV4 format only, for the same reason as above, if the subnet is not configured accordingly, Ecoreach won’t discover such device.
 
 
Resolution:
 
Configure your PC
Your PC must be connected to the same physical network than the devices you want to discover. The WS-Discovery won’t work through routers.
If you don’t know about your devices, configure your PC to get automatically an IP address.
 
Getting IP V4 address of a device:
Using windows explorer, go to the network directory to see your devices. If you right click on the device, you’ll see the IP address (V4 or V6) of the device. If you get the V6 address, you have to double click on the device to open the web browser on your device and go to the IP configuration tab to get the value of the IP V4.
 
Configure your device and you PC in the same sub network
If you want to discover the devices using Ecoreach, your PC and the devices must be configured in the same subnet. To calculate the subnet of an IP address, you have to make a logical AND operation between an IP address and its subnet mask.
For instance, PC at 192.168.1.5 and device at 192.168.2.6 are in the same subnet if mask is 255.255.0.0 (192.168.0.0 for both), but are not in the same subnet if mask is 255.255.255.0 (192.168.1.0 and 192.168.2.0).
Here are some examples of subnets using the couple IP Address and mask:
  • 169.254.10.2 && 255.255.0.0 = 169.254.0.0
  • 169.254.10.2 && 255.255.255.0 = 169.254.10.0
  • 169.254.10.2 && 255.0.0.0 = 169.0.0.0
  • 169.254.10.2 && 255.255.224.0 = 169.254.0.0
  • 169.254.132.2 && 255.255.224.0 = 169.254.128.0
 
 
Tips to retrieve a device not showing up in windows explorer
Connect to the device with a direct Ethernet cable. If your PC is configured with automatic address, it should get an IP address with 169.254.X.Y format. If you cannot see the device, return it to IP factory settings (See  user manual of the device). 
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