On occasion, a popup notification appears on my MPPro screen saying:
"Another device on the network is using your computer’s IP Address (10.0.1.x).
Try connecting again later. If you continue to have problems, change the IP address of this computer or the IP address of the other device. Contact the network administrator of you need more information."
Checking Network prefs, Wireless diagnostic and AirPort Extreme clients list, I find no other wireless device (don't have very many on the network) with the same IP as the computer in question. I do have one wired ethernet wired device on the router but with a non-conflicting IP address.
Curious why this has begun happening (since Sierra update) and how to avoid it. I have done resets/restarts on the Airport Extreme to see if this was some DHCP thing, but no change.
Side Note: I use DHCP reservations on the same page so that I can leave all client devices set for DHCP. This is especially nice for printers, TV receivers, and network probes like the RIPE Atlas device.
aha. Think I found the conflict.
I have a VOIP comm app (Echolink ham radio) set up to use ports 5198-99 and had its "private IP address" set same as host system. changed it to an address outside DHCP range. Thanks for the investigative lead.