Installed Armbian_5.38_Orangepiplus_Ubuntu_xenial_default_3.4.113_desktop.
After a while, namely the clock after 5 work OrangePi Plus 2 disappears from the internal network.
Do not pass the ping, connection to the SSH. But you can connect from the outside through the routed ports of the router to the SSH.

Pings from it pass only to the router (192.168.0.1). Prior to other devices in the local network, pings also do not reach.

This is when the internal network disappeared. Before its disappearance with pings and connections on the SSH, there are no problems.
What could be the problem?

 

armbianmonitor -u - http://ix.io/17Ni

This looks like a problem with the router itself ...

Did you tried to power recycle this router without touching anything on OPi ?

 

I'll wait for the next network failure and try to reboot the router.
I have Mi Router 3.

For the sake of experiment I tried to install the image Armbian_5.38_Orangepiplus_Ubuntu_xenial_next_4.14.14.
The work time is already 21 hours and the network is still running, no problems.

It is interesting that in the previous image is not so.

But with ksenial_next is another problem, there is no sound through the 3.5 connector, but this is already another matter of the topic probably.