[PATCH 01/13] mbssid: add configuration options

Jouni Malinen j at w1.fi
Thu Apr 7 12:47:43 PDT 2022

On Wed, Mar 02, 2022 at 02:26:22PM -0800, Aloka Dixit wrote:
> Add configuration options to enable multiple BSSID (MBSSID) and
> enhanced multiple BSSID advertisements (EMA).
> MBSSID enablement is mandatory to enable EMA.

> diff --git a/hostapd/hostapd.conf b/hostapd/hostapd.conf
> +# Multiple BSSID element support in beacon and probe response frames.
> +# 0 = Disabled
> +# 1 = Enabled
> +#mbssid=0
> +
> +# Enhanced multiple BSSID advertisements support in beacons.
> +# 0 = Disabled
> +# 1 = Enabled
> +#ema=0

Those comments do not make it exactly clear what these do and when these
should be enabled. Furthermore, that dependency on mbssid=1 having to be
set when ema=1 is used could be avoided by using a single configuration
parameter could make more sense with values 0=do not use Multiple BSSID
element, 1=use Multiple BSSID element without EMA, 2=use Multiple BSSID
element with EMA.

It would be important to clearly describe here what is difference
between the Multiple BSSID element being enabled and disabled, i.e., how
that would change the behavior of bss=<ifname> entries as far as the
number of different beaconing BSSs is concerned and how the first BSS is
the one that is going to be the one with transmitted BSSID. It should
also be pointed out that enabling this will result in a large portion of
deployed STAs not being able to connect to the other than the first BSS.

It would be good to move these parameters to the "Multiple BSSID
support" section at the end of hostapd.conf file since that is what this
functionality is all about.

> diff --git a/src/ap/ap_config.h b/src/ap/ap_config.h
> @@ -1107,6 +1107,8 @@ struct hostapd_config {
> +	u8 mbssid;
> +	u8 ema;

A single enum with the three options mentioned above could be nicer for
Jouni Malinen                                            PGP id EFC895FA

More information about the Hostap mailing list