Disappearing Ethernet port

[goathunter]

As a followup, the current Armbian releases work on two of my Pines, but not my third. The symptom is the same on the third. Examination shows that my third Pine was actually manufactured a little earlier than the other two, and the chip numbers are different. Apparently, the Armbian kernel doesn't (properly?) support the older Ethernet chip. So my third Pine is still running the longsleep kernel, and the Ethernet port works fine under that.