Roaming to same BSSID as currently associated behaviour.

Jouni Malinen j
Mon Nov 18 14:54:05 PST 2013

On Mon, Nov 18, 2013 at 02:32:27PM -0800, Ben Greear wrote:
> On 11/18/2013 02:25 PM, Dan Williams wrote:
> > On Sun, 2013-11-17 at 19:11 -0800, Ben Greear wrote:
> >> But, what is the preferred method of roaming if the roam command is
> >> just for testing purposes?
> > 
> > Use one of the bgscan plugins and let the supplicant handle roaming
> > itself based on signal strength.  Or if it's a fullmac driver, the
> > driver will handle roaming.
> For my purposes I want more control over it, so I guess the 'roam' cli
> command will be best.

If I've understood your use case correctly, it would have been very much
in my "testing purposes" category.. ;-)  It is fine to use the roam
command, but you'll need to be more aware of the driver details (and
especially, cfg80211 behavior in this case) when using it. Please take a
look at the commit log of the commit that added this command:

    Add ctrl_iface command for triggering a roam to a specific BSS
    'wpa_cli roam <bssid>' can now be used to test roaming within an ESS
    (e.g., for FT over-the-air). This command will bypass a new scan and
    will select the BSS based on the specified BSSID. It is responsibility
    of the caller to make sure that the target AP is in the BSS table.
    This can be done, e.g., by running a scan before the roam command,
    if needed.

(and yes, that BSS table there is referring to cfg80211 BSS table as
well, i.e., you may need to trigger a scan just before using ROAM; and
obviously, do not call ROAM if you do not want to "roam" even back to
the current AP :-)

Jouni Malinen                                            PGP id EFC895FA

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