The essence of the problem is this.
I work with Orange PC Plus microcomputers. I used to use the Armbian_5.25_Orangepipcplus_Ubuntu_xenial_default_3.4.113 distribution
And so the device address was HW Address: fa: 20: 6d: b5: 65: bd

But when installing new distros Armbian MAC becomes different.
HW Address: 12: 81: ab: 1a: 39: 92
Permanennt HW Address: 12: 81: ab: 1a: 39: 92

I really need the MAC to be like before. And it did not change when reinstalling the OS.
How to do it?

By default both EMAC (100tx) and GMAC (1000tx) use random MAC addresses that change with each reboot. Our first run script fix them this way:

 

(1) https://github.com/armbian/build/blob/master/packages/bsp/common/usr/lib/armbian/armbian-firstrun
(2) https://github.com/armbian/build/blob/master/packages/bsp/common/usr/lib/armbian/armbian-common

(3) http://linux-sunxi.org/Ethernet

I am not strong in Linux configs.

Of course, the material is ready to study, if you tell me that the problem can be solved by replacing some necessary parameters in the first boot files.
and do I understand correctly that the links that you sent relate to the current versions of Armbian? And do not apply to the old versions?