From your message, since you have different MAC addresses on both devices now, I don't know what could be causing it.
However, the root problem re: same mac addresses stems from the fact that mac address is hard-coded in the /boot/uEnv.txt file (so it's on the 50MB fat partition that windows can see). My uEnv.txt for a recently provisioned longsleep ubuntu image looks like this... (which I haven't bothered changing). So in the first instance, it may be easier / worth ensuring it is different there on both pine64s (and not bothering with the /etc/network/interfaces override), or removing it from the uEnv.txt and specifying it in the /etc/network/interfaces config only.
Also, I seem to remember (although this may be from another forum and for a completely different matter) that there was some issue with changing the first three octets from the manufacturer specified one? So maybe only change the last one?
An even easier fix if you're using the minimal Ubuntu Xenial image is to use the Armbian one instead, as IIRC Armbian generates a random mac on first run?
However, the root problem re: same mac addresses stems from the fact that mac address is hard-coded in the /boot/uEnv.txt file (so it's on the 50MB fat partition that windows can see). My uEnv.txt for a recently provisioned longsleep ubuntu image looks like this... (which I haven't bothered changing). So in the first instance, it may be easier / worth ensuring it is different there on both pine64s (and not bothering with the /etc/network/interfaces override), or removing it from the uEnv.txt and specifying it in the /etc/network/interfaces config only.
Code:
console=tty0 console=ttyS0,115200n8 no_console_suspend
kernel_filename=pine64/Image
initrd_filename=initrd.img
ethaddr=36:c9:e3:f1:b8:05
Also, I seem to remember (although this may be from another forum and for a completely different matter) that there was some issue with changing the first three octets from the manufacturer specified one? So maybe only change the last one?
An even easier fix if you're using the minimal Ubuntu Xenial image is to use the Armbian one instead, as IIRC Armbian generates a random mac on first run?