Details about the -b option of wpa_supplicant.

[Nicolas de Pesloüan]

Hi,

Can someone explain the exact expected effects of the -b option of 
wpa_supplicant.

I'm currently trying to bond (using the Linux bonding module) an 
Ethernet NIC and a Wifi adapter.

Now that I found the -b option of wpa_supplicant, things seems to go 
better. But when the wifi interface is not the active slave of bond0, 
the Wifi link drop down from time to time, and fail to reestablish.

For as far as I understand, the -b option is required to be able to 
*receive* the frames involved in the link establishment, because those 
frames are made available on the master interface not on the slave 
interface. Am I right ?

If right, is the master interface used to *send* frames involved in link 
establishment ?

If not, why having the wifi slave interface not the active slave of 
bond0 is a problem ?

I found a small script that use wpa_cli to ensure every second that the 
wifi link is up, and force the wifi interface to become the active one 
when the link is down, to give a chance to wpa_supplicant to reestablish 
the link, then go back to the previous active slave.

This might work, but by design, cause some lose of packets every time 
the  wifi link fall down, even if the Ethernet link is up and running at 
the same time.

Any advices ?

	Nicolas.