single radio interface, BSS count 2

Jouni Malinen j
Sun Feb 21 02:02:57 PST 2010

On Sat, Feb 20, 2010 at 04:34:49PM -0600, green wrote:

> I would like to provide 2 wireless networks, one open, one WPA2.
> The first (open) network works fine, but when I add the second (no wpa set 
> up yet) I get:
> BSS count 2, BSSID mask ff:ff:ff:ff:ff:fe (1 bits)
> Invalid BSSID mask ff:ff:ff:ff:ff:fe for start address 00:21:91:01:11:6f.
> Start address must be the first address in the block (i.e., addr AND mask == addr).

hostapd will by default try to assign consecutive addresses for the
virtual interfaces and require that the BSSID mask can generated in a
way that allows the driver to use simple operation to figure out which
frames should be acknowledged. This requires that the lowest end bits of
the MAC address are zeros which is not the case here.

You can either change the MAC address of the wlan0 interface before
starting hostapd (e.g., use a locally administered address
02:21:91:01:11:60) or set the MAC address of the virtual interface
explicitly (e.g., with bssid=02:21:91:01:11:6f after the bss= line in

Jouni Malinen                                            PGP id EFC895FA

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