MIME-Version: 1.0
In-Reply-To: <20090812100416.744dc5ba@nehalam>
References: <20090812100416.744dc5ba@nehalam>
From: "Luis R. Rodriguez" <mcgrof@gmail.com>
Date: Wed, 12 Aug 2009 10:25:34 -0700
Message-ID: <43e72e890908121025p75b141b6o86c30518bf9de7ea@mail.gmail.com>
Subject: Re: Multiple SSID
To: Stephen Hemminger <shemminger@vyatta.com>
Cc: "John W. Linville" <linville@tuxdriver.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	linux-wireless@vger.kernel.org
Content-Type: text/plain; charset=UTF-8
Sender: linux-wireless-owner@vger.kernel.org

On Wed, Aug 12, 2009 at 10:04 AM, Stephen
Hemminger<shemminger@vyatta.com> wrote:
> I have a dumb questions. How does one setup multiple SSID's with
> current (ie not madwifi) wireless API?
>
> 1. I assume need to run multiple instances of hostapd with different
>   config. Will that work?

Yes. But the next question is how to create new wlan%d AP interfaces.
That is answered below.

> 2. Since IP address is attached to device (wlan0), how can each SSID
>   have different IP address? Use vlan's?

The new 'iw' [2] utility could be used to create monitor interfaces or
ad-hoc interfaces for example. We decided to only allow you to create
an "AP" type of interface with a utility that handles the MLME in
userspace, such a utility is hostapd. You will need to use the nl80211
driver with hosatpd [2]. We have documented the supported wireless
modes in our wiki [3], I suppose that could use some updating.

Anyway I believe AP-enabled devices right now only support creating 1
AP interfface. I believe the exception to this right now is ath9k
through the private virtual interface stuff Jouni created, but to be
honest I have to go and review that to make sure you can create 2 APs.

Typically drivers (MadWifi) which supported multiple BSSs (therefore
with two SSIDs) would allow you to do this by creating BSSes on the
same channel. The ath9k virtual interface thing allows you to create
interfaces on *separate* channels, and provides its own scheduler,
which you can tune, for switching back and forth.

[1] http://wireless.kernel.org/en/users/Documentation/iw
[2] http://wireless.kernel.org/en/users/Documentation/hostapd
[3] http://wireless.kernel.org/en/users/Documentation/modes

> 3. Do vlan's work on wireless (ath9k)?

Not sure what is required to support vlans.

  Luis