Random ethernet network connectivity problems

[dec]

I have an old S905X device (with coreelec 9.2.5) which recently started to have problems with ethernet network interface. From time to time the interface decides to go down, and the device loses connectivity. It is solved by a reboot, and sometimes it recovers by itself. Usually the problem is discovered by a failure to play video streams from the network. Here is an example from kodi logs in this case:

ix.io/2LEg

At the same time, I see the following in system logs:

ix.io/2LEe

Note logs towards the end, starting at 15:28:26.

What can be done to solve this problem?

[Portisch]

Without looking into the logs (thanks for providing them!):
try a clean fresh install,
exchange power supply,
exchange LAN cable,
if WLAN change channel,
try Amlogic-ng,
exchange Router,
exchange S905X

[timfolk]

I have a similar issue with Vim3. It’s hooked to wired network and files stored on win10 PC. It’s also on a CEC so goes to sleep mode when I turn off the TV. Currently using latest nightly but it’s been like that for a while now.
Every now and then I get no connectivity when waking up the system, happened once while it was still on.
The only thing that solves it is rebooting the PC, sometimes several times. Both Vim and PC are on static internal IPs.

[cubimol]

I have already answered you on another topic. There are two reasons that can cause this: two or more devices using the same IP, or malfunction of the device or the RJ45 ethernet connector.

[dec]

Each device on my network has a fixed static ip, therefore multiple devices using the same ip is not a problem. Of course it is always possible that there is a hardware problem either with the device or with the connector, but there may be other reasons - and I want to find out the real reason for the problem, not just guess. If it is possible to understand the root of the problem, it will save a lot of work. I hoped that maybe somebody may be familiar with the exact cause of the problem - this is actually the reason for the logs: maybe a particular line there may provide enough clue.

[cubimol]

My experience tells me that you have a duplicate IP, even if you think that it is not, or your router unexpectedly changed the IP of your CoreELEC device. Check the IP address of all the devices on your home network one by one, or change the IP of your CoreELEC. The other possibility that you think is absolutely unlikely.

Warning: The assignment of static IP addresses must always be done from the router to avoid assigning errors.

[Sholander]

Or just for testing, on the box instead of fixed IP set it to “Automatic” and let the router assign a free DHCP IP address from the pool…