UM3 (E) LAN problems? Group of UM3 acting "weird"

[twlum 3]

I don't expect a solution but I figured I would lay out what I have happening and see if anyone has suggestions.

 

I manage a makerspace at a university and we have a workgroup of 4 UM3 connected through LAN, each with their own dedicated IP address. I have managed this group for about 5 years with only an occasional issue, until this week.

 

The group of 4 UM3, initially they were on a mix of older firmware but with the issues, I updated them all to the latest "maintenance" firmware to rule out any incompatibility problems.

I first noticed an issue when a printer was labeled as "Unreachable" in Cura 4.13.1 under the monitor tab. I restarted the printer and it would initially boot, show the Ultimaker logo, and then just a black screen and green ring around the controller circle. I let it sit for an hour but nothing. Eventually after a lot of experimenting, I realized that if I unplugged the LAN cable, the printer would start up as normal. I then plugged the LAN cable back in and it showed up in Cura, but...later it was unreachable again.

 

That is when I thought maybe it was the differing firmware so I updated them all to 5.3.0.

 

After the updates, they still wont boot with the LAN cables plugged in but I can unplug the LAN, boot them and plug them back in. Now they are all unreachable in CURA BUT I can still click on the camera and get a live video from each printer so the network must be working somewhat?!?!  If I click on Manage Printer button in Cura, it launches a web browser and then I choose "Print Jobs" tab in Ultimaker Digital Factory, they all show "This printer currently can't be reached" but once in a while, one will connect and then disconnect again almost immediately.

 

My next step is to maybe take them home or somewhere where I can put them on another network to see if it's a network issue or a printer group but I really don't want to go through that amount of troubleshooting if someone had a better idea. I plugged my laptop into the LAN cable and my computer got out into the network without an issue so I don't think it's that. I was also thinking of trying to use the WIFI grouping but setting up that in the University is a bit of an issue since me have to register each device and I don't think I could keep a specific IP address for each printer or at least the amount of work it would entail seems greater than figuring out why the LAN that was rock solid for 5 years now won't work.

[twlum 3]

I have been troubleshooting this issue more this morning and decided to reset the printers to factory settings and try using just a WiFi connection. The printer was stable and able to be seen by Cura all morning. I then connected the LAN cable and tried switching the connection and the printer was immediately lost. Kind of running out of ideas except to bring a few printers home and see if they behave similarly on another network.

[StephanK 30]

Strangely enough, I noticed this same behavior from UM2+Connect (sans Camera, which the UM2+C does not have)..  It seems to randomly drop off the LAN for no apparent reason. Used to work just fine, just started recently. It might coincide with switching to Cura 5.

Did you find out more about this issue meanwhile?