Connecting to 2.4G when both 2.4G and 5G network is available

[Dan Williams]

On Fri, 2016-06-03 at 16:38 +0530, Johncy Bennette wrote:
> Hi,
> I have a router that is broadcasting the same SSID on both 2.4G and
> 5G
> networks. My requirement is if a router has only 5G then my device
> has
> to connect to the router. If the router has both 2.4Ghz and 5Ghz, how
> can I tell my device to stay connected to 2.4G. Is there any
> configuration in wpa_supplicant to achieve this?

You can supply a frequency list (the freq_list config option) in the
network block that includes all 13 2.4ghz frequencies, and the
supplicant will ensure that it only uses those.

The only caveat is that some drivers handle roaming in firmware instead
of allowing the supplicant to control it, so those might not respect
the freq_list.  But drivers based on mac80211 should respect it.

Dan