Re: [Bridge] Hardware requirements for bridging wired+wireless together

[Stephen Hemminger <shemminger@linux-foundation.org>]

On Tue, 18 May 2010 16:38:54 -0700
"Umar Qureshey" <umar.qureshey@lantronix.com> wrote:

> -----Original Message-----
> From: Nicolas de Pesloüan [mailto:nicolas.2p.debian@free.fr] 
> Sent: Tuesday, May 18, 2010 12:32 PM
> To: Umar Qureshey
> Cc: bridge@lists.linux-foundation.org
> Subject: Re: [Bridge] Hardware requirements for bridging wired+wireless together
> 
> Umar Qureshey wrote:
> > Hi,
> >
> > I have been trolling the 'net as well as the archives of this list for
> > quite a while now.
> >
> > I am still unclear on the requirements for getting an Ethernet and
> > Wireless interface to bridge together.
> >
> > Currently, I am working with an esoteric radio that only supports Ad-Hoc
> > and Managed modes.  There seemingly is not support for WDS (Wireless
> > Distribution System) on this radio.
> >
> > I have been trying to bridge my eth0 and wlan0 but it doesn't seem to
> > work.  Currently, my commands to get the bridge up are:
> >
> > ifconfig eth0 0.0.0.0
> > ifconfig wlan0 0.0.0.0
> > brctl addbr br0
> > brctl addif br0 eth0
> > brctl setfd br0 1           #BusyBox version of brctl doesn't take 0 as
> > a time parameter so I change it to 1 (sec)
> > ifconfig br0 up
> > wpa_supplicant -Dwext -iwlan0 -bbr0 -c/root/wpa_supplicant.conf
> 
> I think you forgot to add wlan0 to the bridge:
> 
> brctl addif br0 wlan0
> 

I believe bridging in station mode won't work (usually).
Recent kernels even reject the attempt.

There are exceptions with some devices and if the stack supports WDS
(which Linux wireless doesn't yet).

There are some cases like VMware that appear to do MAC level NAT
(ie replace Ethernet address), but the regular kernel doesn't support that.