Re: Proposal: enable stateless persistant network interface names

[Marvin Renich <mrvn@renich.org>]

* Martin Pitt <mpitt@debian.org> [150509 05:27]:
> TBH, hotpluggable USB network adapters which change all the time sound
> like a corner case in a server world where you have hand-written
> config files referring to interface names. They are of course common
> on the client side, but there stable interface names don't matter at
> all. But see below.

I disagree that stable interface names do not matter for USB adaptors
for consumer laptops.  I have owned two laptops where the on-board WiFi
adaptor was too new to have reliable Linux drivers until 6-12 months
after I purchased them.  While waiting for the Linux drivers, I used a
USB WiFi dongle that has good kernel support.  I have plugged the
adaptor into different USB ports based on where my laptop was situated
wrt varied surroundings.  I suspect (with no real data to back it up)
that the biggest use of USB WiFi dongles on consumer machines is when
the on-board WiFi doesn't work for some reason (too new or broken).  In
this case, it is often the main internet connection and a stable name is
important.

To address the statement about swapping a new adaptor for a broken
adaptor (in server or client desktop), this happens so rarely and
already requires a significant effort (opening the machine, etc.) that
editing the udev persistent network rules is not an issue.  This does
not make MAC-based names less usable in that context.

I'm not sure what the correct solution is, but from what I have seen in
this thread, I have become convinced that [ifnames] is not it.  (That is
a change from my initial perception.)  I would like to discourage the
proposed change.  Perhaps some compromise where ifnames is used for
PCI-based devices and MAC is used for USB devices might work; I'm not
sure.

I have no problem with learning a new naming convention for the devices.
Note that the naming convention makes no difference for programmatic
use; any programmatic use should query the specific properties of the
device that are important to the program.  The naming convention is only
relevant to the sysadmin, where it helps to identify properties in which
the sysadmin might be interested (e.g. wired vs wireless).

...Marvin