MAC address change

I'm running openmediavault 5.5.9 on an odroidn2 with armbian 20.08.1.

Recently I ran the updates and this caused the MAC address of the eth0 adapter to change. Since I really rely on it to be static I set

iface eth0 inet dhcp

hwadress ether xx:xx:xx:xx:xx:xx

in a respective file in /etc/network/interfaces.d/ to force this.

However, this did not resolve the issue. Can someone tell me why the hwaddress changed in recent updates and how to keep it static?

Thanks much

It's not a conclusion I came to but a fact. As is well known, MAC addresses can be altered, see here for example. Anyway, can someone contribute something as to why recent OMV/armbian updates would do this and what the mechanism in this case is to keep the hwaddress fixed?

Thanks

This is not about altering the hardware address in the actual hardware.

Maybe I didn't describe my problem adequately: after running the aforementioned updates the eth0 device was registered at my DHCP server with a different MAC address, resulting in the DHCP server assigning a different IP address, messing up the network configuration. This is not unheard of. What I'm trying to figure out is how to manage, software-wise, keeping the hwaddress stable with openmediavault 5.5.9/armbian 20.08.1. The method I posted obviously doesn't do the trick in my situation.

As an example: /sbin/ifconfig before the update gave

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500

[...]

ether xx:xx:xx:xx:xx:xx txqueuelen 1000 (Ethernet)

while after the update

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500

[...]

ether yy:yy:yy:yy:yy:yy txqueuelen 1000 (Ethernet)

Thanks much for your suggestions, I'll check the netplan configuration. Do you know why setting

allow-hotplug eth0

iface eth0 inet dhcp

hwaddress ether 00:1e:06:42:4a:6f

in e.g. /etc/network/interfaces.d/hwaddress doesn't work? According to /etc/network/interfaces files in interfaces.d/ should be sourced.

Pasting the new address in the dhcp list of the router is of course what I did to resolve this for now. But should OMV keep changing the MAC it would be a little awkward doing this repeatedly due to other configuration tied to the MAC address that my set-up requires (open ports, etc).

And yes, you're right, I could set a static IP address, so far I just preferred having the router assign the addresses and let it assign the same to certain machines.

Thanks again.