[systemd-devel] udev breaks hostap linkage of raw/user interfaces, causing wpa_supplicant problems

Michael Biebl mbiebl at gmail.com
Mon Mar 16 09:35:42 PDT 2015

2015-03-16 17:25 GMT+01:00 David Herrmann <dh.herrmann at gmail.com>:
> Hi
> On Mon, Mar 16, 2015 at 4:48 PM, Thomas Richter <thor at math.tu-berlin.de> wrote:
>> If udev comes into play, it renames wlan0 to wlan1, because wlan0 was
>> already taken from a previously installed ipw2200 card that is no longer
>> in the system. Hence, I have now the network interfaces wifi0 and wlan1,
>> and that confuses wpa_supplicant to an amount that it can no longer
>> authenticate the connection. Why precisely that is the case I do not
>> know, but naming both interfaces the same resolves the problem.
> Ok, forget my previous mail, your issue is only related to the wext
> driver, not the hostap extensions.
> Up front, upstream udev never renames wlan0 to wlan1.

Well, "current" upstream udev, with persistent interface naming
enabled, would rename italso, it would just chose a different name,
one which is not in the same wlanX namespace.
If that alone is suffcient to not trigger Thomas problem, I dunno.

That said, Thomas is talking about udev 175 (Debian wheezy), where
udev upstream did infact still ship the udev rules which renamed wlan
interface within the same namespace.

 This is a
> downstream problem.

Please don't be so quick always blaming downstream.


Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?

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