Re: Ethernet trouble
On Wed 29 Jan 2020 at 16:52:19 (-0700), ghe wrote:
>
> (Blush, blush)
>
> I took those boards out, and the names went back to what I'd expected
> them to be.
>
> I have no idea why. It doesn't make sense to me -- absolutely nothing
> changed that had anything to do with Ethernet interfaces. The OS and the
> BIOS didn't change either.
>
> I put them back in, and the names changed.
These boards, do their PCI addresses have the save bus number but
different slot/device numbers? dmesg or kern.log will give you
those: they look like NN:DD.F optionally preceded by DDDD:, where
DDDD is the domain (typically 0000), NN is the bus, DD the device
of slot, F the function(s) provided by that card, eg
pci 0000:00:0e.0: [10ec:8139] type 00 class 0x020000
If so, and if they're the only devices on that bus, then it seems
likely that when the bus is unpopulated, it doesn't get enumerated,
whereas when you insert a card, the bus has to be enumerated, and its
enumeration number is ≤ 6, pushing those ethernet buses up by one.
> When I originally installed the boards, the names didn't change.
> (Buster, IIRC, was Testing back then.)
>
> I've written a lot of software, but my worst bugs never did anything
> like this. And I've been on Debian OSs for a long time, and I don't
> remember anything like this. That's what Sid and Testing are for, but
> Stable's for Internet servers and banks.
AIUI it's nothing to do with the OS as these decisions are made by
the firmware on the mobo. Juggling cards in a mobo can even outwit
the BIOS so that the POST won't succeed: I've had mobos where I've
had to empty the box, power-up and save the settings, add one card
and repeat, add the next and so on, all to get a box with the cards
I wanted, located where I wanted them.
People who set up servers and banks either know this stuff or get
their kit ready-built by the supplier.
Cheers,
David.
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