2008-09-29 16:25:11

by Peter Niemayer

[permalink] [raw]
Subject: "ip link set address" fails with ath5k and newer madwifi drivers

Hi all,

I recently noticed that changing the MAC address of an
atheros WLAN adapter fails with all ath5k and newer
madwifi drivers.

To reproduce, just say something like

ip link set <yourdevice> address 11:22:33:44:55:66

before attaching to your access point. This worked
fine with old madwifi drivers. (Alas, I cannot narrow
down "old" much finer, must have been ~2 years)

With a current ath5k driver, the attachment to the AP
fails, and if I look into the NIC registers using
athtool, I can see the new MAC address has not consistently
been stored there.

With a current madwifi driver, the attachment to the AP
works, and the NIC registers do contain the newly set
address. But any further communication fails, as packets
sent from the local machine to the AP contain the wrong
(old, original, before "ip link set ...") MAC source
address.

Is this a known problem? Does anybody have a hint on
where to look for a resolution?

Thanks in advance,

Peter Niemayer