How to work with ADDP device discovery protocol and devices running embedded Linux like ConnectCore, ConnectCard, Digi Connect ME 9210

In order to be able to search for embedded Linux devices in your local network with the ADDP protocol using broadcasts/multicasts you need to add the "addpd" to your root file system.
This can be done in Digi Embedded Linux ESP in a rootfs project just by adding application "ADDP" in the project configuration page. This will also automatically launch the "addpd" on startup during runtime. You can check it is running on the embedded device with "ps". You also will see addp entries in /var/log/messages about received discovery requests.

However discovery will not work out of the box, since on the embedded Linux device you will need to add some routes to enable the broadcast messages to be received and sent by ADDPd.
To add those routes modify /etc/init.d/S81addpd.sh by adding for example:

# route add -net 224.0.0.0 netmask 240.0.0.0 dev eth0
# route add default dev eth0

such that your routeing table will look similar to:
Destination    Gateway Genmask ..
192.168.42.0 * 255.255.255.0 U 0 0 0 eth0
224.0.0.0       * 240.0.0.0         U 0 0 0 eth0
default           * 0.0.0.0             U 0 0 0 eth0


Now you should be able to discover the device from Linux ESP->Device Options->Device Discovery.
You might also want to use a stand alone Java application which runs under Linux and Windows.

Make sure the firewall on the PC running the device discovery tool allows UDP broadcasts/multicasts or is switched off, see also What ports are used with Digi's Device discovery ADDP protocol?

Actually this is ok to determine the IP address you device has got in a DHCP subnet.
You also can discover devices with fixed IP and change them to DHCP through the device discovery tool (DDT).

Known bugs:
You will not be able to change the static IP address to a different one through the DDT.
If your device has got no IP address at all (e.g. missing DHCP server) it will not reply to the recovery broadcasts, although it received the discovery request (see /var/log/messages).
Last updated: Jun 24, 2019

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