Re: Getting a stable MAC address for a RPI CM3+ with ue0 interface

On Sep 20, 2023, at 10:53, Patrick M. Hausen <pmh@hausen.com> wrote:

Hi folks,

> now that 14 is in beta and there are packages (yeah!) I try to reactivate my
> TuringPi 1 cluster. This little thing is 7 RPI CM3+ with a common power
> supply, one USB ethernet for each of them and a switch with a gigabit
> uplink to the outside world.
> 
> I noticed that the MAC address changes with every reboot, which is
> more than slightly annoying. I'd like to have the standard RPI MAC
> address calculated like this for each of my CM3+:
> 
> 0xb827eb000000 | (<serial number> & 0xffffff)
> 
> Linux does this by default in every distribution I came accross.
> Isn't this "the way" for RPIs?
> 
> The problem: whenever I try to set the MAC address via
> 
> /etc/start_if.ue0:
> 
> /sbin/ifconfig $1 line b8:27:eb:11:22:33
> 
> I lose network connectivity. I found some older discussion (for FreeBSD 11)
> suggesting to set promisc - that would match my observation that I
> see DHCP requests coming from the PI (with correct MAC address) and
> answers from my OPNsense, but the latter do not seem to reach the PI.
> 
> What is the correct way to get any stable MAC address and why don't
> we do it like Linux does, which for once is perfectly sensible, IMHO.

Quoting a post from a "Raspberry Pi Engineer & Forum Moderator"
(PhilE) from https://forums.raspberrypi.com/viewtopic.php?t=327562 :

QUOTE
Re: /boot/cmdline.txt help
Thu Jan 13, 2022 8:35 am

And on all Pis you can use the config.txt setting "force_mac_address":

force_mac_address=aa:bb:cc:dd:ee:ff
END QUOTE

That makes the live dtb match and is the earliest assignment
available, before any external visability.

===
Mark Millard
marklmi at yahoo.com