Didier Kryn <kryn@???> writes:
> Le 05/10/2015 18:54, Rainer Weikusat a écrit :
[...]
>> A file
>>
>> /etc/udev/rules.d/75-persistent-net-generator.rules
>>
>> can be created (on Debian up to wheezy at least) to avoid this "install
>> the system to new hardware and get a whole bunch of new ethN instead of
>> the onese which aren't available anymore" mess altogether.
> This logic was implemented in older versions of Debian by the mean
> of the file you say, but this file is not installed on my Debian
> Wheezy; therefore I am afraid they have implemented the same logic in
> some hidden place.
By default, this file doesn't exist. But the udev package contains a
/lib/udev/rules.d/75-persistent-net-generator.rules
which is responsible for "writing net rules" and creating the /etc file
of the same (base-)name overrides that.
[...]
>> It's not that simple as MAC addresses are neither necessarily persistent
>> nor necessarily unique. Eg, by default, so-called "virtual ethernet pair
>> interface" (used to connect containers to physical interfaces via bridge
>> interfaces) use random MAC addresses. It's also often/ usually possible
>> to change the MAC address of an interface. That's just something the
>> people who came up with the previous less-than-bright idea didn't think/
>> know about at the time they did come up with it (according to the 'code
>> comment' documenting the new scheme).
>>
> Yes, changing the MAC address of a real network interface can be
> done to fool a DHCP server (I don't see any other reason), but this is
> done in user space, after the kernel has registered it.
"Once upon a time in the past", I deal with a SoC running Linux (2.4)
where the interface MAC addresses had to be programmed into the hardware
based on date read from the flash ROM ...
::
Re: [DNG] Purpose of an OS: was net…
