Thanks for helping me figure this out!

I have tried to use the proposed, proper way of doing this using:

net_mgmt(NET_REQUEST_ETHERNET_SET_MAC_ADDRESS, iface,
&params, sizeof(struct ethernet_req_params));

Unfortunately the build will fail due to: undefined reference to `net_mgmt_NET_REQUEST_ETHERNET_SET_MAC_ADDRESS' when trying to use it.

I have added CONFIG_NET_MGMT=y to prj.conf.

Do I have to add more or could it be that my platform (nucleo_f767zi) lacks support for this feature?

/Anders