Re: duplicate MAC - Re: 13.1R problems on Pi3

On 2022-Jul-5, at 16:34, bob prohaska <fbsd@www.zefox.net> wrote:

> On Tue, Jul 05, 2022 at 07:02:18AM -0700, Mark Millard wrote:
>> 
>>> So for you I would guess:
>>> 
>>> ifconfig_ue0="ether ??:??:??:??:??:?? inet 50.1.20.28 netmask 255.255.255.0"
>>> 
>>> 
> 
> I tried a few variants, all produced a dead connection. 
> 
> Using  one like you suggested:
> 
> # ethernet address increased by 1 in the last digit
> ifconfig ue0="ether b8:27:eb:71:46:4f inet 50.1.20.28 netmask 255.255.255.0"
> 
> produced a flood of errors during boot:
> ifconfig: interface ue0=ether b8:27:eb:71:46:4f inet 50.1.20.28 netmask 255.255.255.0 does not exist
> 
> There was clearly no network connectivity, but the serial console
> remained responsive. The host sharing the same MAC address exhibited
> no connectivity problems. 
> 
> 
> Another suggestion was found in an old forum post, assigning the IP
> in the usual fashion but adding an alias:
> 
> ifconfig_ue0="inet 50.1.20.28 netmask 255.255.255.0" 
> ifconfig_ue0_alias0="link b8:27:eb:71:46:4f"
> (trading ether for link had no effect)
> 
> resulted in the gateway (and everything else) being unreachable. 

I also later sent notes about using the RPi* firmware's
config.txt to assign a MAC address to an RPi* . Have
you tried that? It is not in the main RPi* documentation
but RPi* engineers talk about it in the forums.

QUOTE
I've found references to an undocumented control in config.txt :

force_mac_address=??:??:??:??:??:??

See, for example, https://forums.raspberrypi.com/viewtopic.php?t=327562

Apparently, force_mac_address controls what value shows up in
the device tree for what the ethernet0 alias points to in the
device tree.

Note that having a odd .dtb file could lead to force_mac_address
not working. (The RPi* firmware reads the file and then makes
a device tree with some modifications applied.)
END QUOTE


===
Mark Millard
marklmi at yahoo.com