Date: Tue, 5 Jul 2022 17:14:26 -0700 From: Mark Millard <marklmi@yahoo.com> To: Karl Denninger <karl@denninger.net> Cc: freebsd-arm@freebsd.org Subject: Re: duplicate MAC - Re: 13.1R problems on Pi3 Message-ID: <7663F129-6A84-469C-B89A-F24142E3CEEE@yahoo.com> In-Reply-To: <0cd9ee13-9340-8bc4-2b92-171ca83534ee@denninger.net> References: <20220704003639.GA1165@www.zefox.net> <8820A9EC-A25E-4D0A-9F8F-52114E58B66F@yahoo.com> <6c377413-9430-54d2-3f92-1215055ca30a@denninger.net> <20220704152834.GA1771@www.zefox.net> <7ce87eef-ded5-8b00-3f11-14407b8af78d@denninger.net> <20220704182526.GB1771@www.zefox.net> <212C86C0-17DB-45F5-A59D-8BDC1932378E@yahoo.com> <1645012198.135.1657014956867@localhost> <6B24FF55-7010-40ED-B32B-AA46F0E7ED80@yahoo.com> <20220705233440.GA9228@www.zefox.net> <0cd9ee13-9340-8bc4-2b92-171ca83534ee@denninger.net>
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On 2022-Jul-5, at 16:37, Karl Denninger <karl@denninger.net> wrote: > On 7/5/2022 19:34, bob prohaska wrote: >> On Tue, Jul 05, 2022 at 07:02:18AM -0700, Mark Millard wrote: >>=20 >>=20 >>>> So for you I would guess: >>>>=20 >>>> ifconfig_ue0=3D"ether ??:??:??:??:??:?? inet 50.1.20.28 netmask = 255.255.255.0" >>>>=20 >> =20 >> I tried a few variants, all produced a dead connection.=20 >>=20 >> Using one like you suggested: >>=20 >> # ethernet address increased by 1 in the last digit >> ifconfig ue0=3D"ether b8:27:eb:71:46:4f inet 50.1.20.28 netmask = 255.255.255.0" >>=20 >> produced a flood of errors during boot: >> ifconfig: interface ue0=3Dether b8:27:eb:71:46:4f inet 50.1.20.28 = netmask 255.255.255.0 does not exist >>=20 >> There was clearly no network connectivity, but the serial console >> remained responsive. The host sharing the same MAC address exhibited >> no connectivity problems.=20 >>=20 >>=20 >> Another suggestion was found in an old forum post, assigning the IP >> in the usual fashion but adding an alias: >>=20 >> ifconfig_ue0=3D"inet 50.1.20.28 netmask 255.255.255.0"=20 >> ifconfig_ue0_alias0=3D"link b8:27:eb:71:46:4f" >> (trading ether for link had no effect) >>=20 >> resulted in the gateway (and everything else) being unreachable.=20 >>=20 >> Thanks for writing! >>=20 >> bob prohaska >>=20 > Crap - you have to see if you can get u-boot (e.g. in config.txt) to = do it then.... config.txt is for the RPi* firmware. I've sent notes about doing this earlier. U-Boot is not part of the RPi* firmware, it is an optional, separate addition. (An alternative is EDK2 UEFI/ACPI software.) FreeBSD choose to use U-Boot instead of EDK2. Some linux based distributions do not use either. But all use some vintage of RPI* firmware. > that's not supposed to happen (manufacturing two devices with the same = MAC address) and is EXTREMELY not-nice for the very reason you've = discovered. Bob P. has not reported on what a RaspiOS reports for: # vcgencmd otp_dump Parts of the output should be interesting relative to the duplication if he can generate and capture the output. > Linux's boot line has an override available for it, so there IS a way. Quoting a prior message that avoid even boot line use: I've found references to an undocumented control in config.txt : force_mac_address=3D??:??:??:??:??:?? See, for example, https://forums.raspberrypi.com/viewtopic.php?t=3D327562 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 While the official documentation does not cover it, RPi* engineers talk about it on the forums at times when supporting people with problems. =3D=3D=3D Mark Millard marklmi at yahoo.com
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