I have been struggling with this for more than 6 months. My MyCloudEX2Ultra 2-bay NAS with 2 6 TB disks worked flawlessly for 2 1/2 years (locally, via my Android phone and iPad, and the WD web interface). Then I shut it down because I needed to do some electric work in the house. After the restart it was visible as ever, but after some minutes it suddenly disappeared from the network.
What I do not understand is why the thing would work flawlessly for months and months without the slightest hiccup, then drop off the network after an orderly shutdown and restart when all settings remain identical. I also don’t understand why in such cases trying to access the dashboard in my browser would give me a “Connection refused” error message. Apparently, the unit is still doing something, but it is not accessible via browser, Windows, o the cloud. Finally, the Media server is usually still accessible for a while when the dashboard is not, but it too will after an hour or so succumb to whatever is causing this problem. Mind you, I am on my second unit (warranty replacement) and seeing the same weird behavior as on the previous one.
While this is happening the drive will not go into sleep mode any more. All thre LEDs in front are steady blue. There is lots of network activity on the NIC in the back. After I power-cycle the NAS (there is no other way to restart it when it hangs), it will be accessible for a short while (15-30 minutes) then the same symptoms.
With the help of WD support and this forum, I tried 50 different things, including static IP, enbling SMB1, disabling sleep, turning off various services, connecting it directly to the router rather than a switch, turning off the firewall, 4-sec. reset, 40-sec. reset, but only the 40-sec. reset restores functionality (with sleep enabled), until I have to shut down the device again for some reason. Another 40-sec. reset restores the connection, but I cannot be doing this every time I restart the darn thing.
Since the NAS was still under warranty I got a free replacement from WD. I set it up and it worked flawlessly for 4 months, until I purchased a UPS and had to shut the NAS down to connect it. I was obviously half expecting this, and by now the device is out of warranty. So it is time for another 40-sec. reset.
I will never buy anything from WD again. These devices are not cheap, they cannot be used as other Linux boxes from QNAP etc., and support is completely clueless. For instance, why would I need to mess with network, firewall, IP etc. settings when the darn thing works flawlessly for months, and after a restart continues to work for a while, it then drops off the face of the earth? The forums are full of these issues, yet WD does nothing substantial to address them.
I use a static IP on the router mapped to the MAC address of te NAS.
The NAS is set to get its network config via DHCP from the router.
Workgroup name is unchanged (“Workgroup”)
Time zone is set to my local time zone (Vienna)