Hidden SSID/BSSID cache

[Jouni Malinen]

On Mon, Nov 07, 2011 at 05:19:37PM -0800, Simon Barber wrote:
> I use a Ubuntu laptop at work, and the corporate WLAN uses a hidden 
> SSID. Every day I connect at the same place, and wpa_supplicant seems to 
> do an initial scan, then try to scan for the hidden SSID. This takes 
> some extra time. Since I regularly use the same APs would it be possible 
> to extend wpa_supplicant to persistently cache the BSSID->hidden SSID 
> relationships it learns (in a file). This way the next day I open my 
> laptop the initial scan will find the BSSID of the AP I normally use, 
> and learn from the cache that it can immediately attempt to associate 
> with that BSSID, skipping the second scan, and resulting in a faster 
> connection.

I don't see any particular reason for doing this; more generic approach
would be to just make the initial scan use active scan for the specific
SSID (or set of SSIDs if you happen to have multiple such networks
configured).

This should actually already work with nl80211 since it allows multiple
SSIDs to be included in the scan request.. Have you tried that?

-- 
Jouni Malinen                                            PGP id EFC895FA