Re: wlan and bridges

On Sat, 25 Apr 2026 at 03:31, Philipp <satanist+freebsd@bureaucracy.de> wrote:
>
> Hi
>
> I would like to use a wlan device in a bridge (to setup a vm[0]). After
> a bit testing and searching I found an old thread[1] which explaines
> this is not working at the moment.
>
> So to get my VM working I now used my WiFi range extender with an
> ethernet port and used the setup from the handbook. Now it's working. So
> this cheap WiFi extender can somehow support switching as a wifi station.
> I would like to have something similar directly with freebsd.
>
> Now there are two questions:
>
> 1. What does this WiFi extender exactly?

It's likely using WDS - 4 address wifi frames - which has source/dest
ethernet and source/dest wifi addresses.

> I would guess it set all 4 mac addresses in the WiFi frame. But I'm new
> to WiFi debuging so I don't know how I can check this.

You could use tcpdump on your NIC if it supports dumping the raw frames

# tcpdump -ni wlan0 -y IEEE802_11_RADIO -vv -ee

> 2. What needs to changed on freebsd to support this?

Oh, I thought I did a write-up at some point for freebsd WDS support.
The problem is both sides
need to support WDS and WDS interoperability was never REALLY a thing
that vendors pushed for.

The other way this gets solved is that the extender would "pretend" to
be multiple stations, one
per ethernet address. That's called "ProxySTA" and it's something
Apple used to do with their
Airport devices. No we don't support this.

> I'm not familiar with the freebsd wlan (and networking) implementation,
> so it would be nice to have some staring points.

The real challenge here is that there's no interoperability guaranteed
between a FreeBSD device
with a station acting as a WDS relay and a random vendor AP acting as
a WDS AP. Most APs don't
even support configuring WDS in the first place and will drop WDS frames.

Your best bet is to create a bridge, assign it a local IP and use NAT
through your ethernet/wifi
IP addresses. That's what I do on my laptops when running VMs.

> Philipp
>
> [0] https://docs.freebsd.org/en/books/handbook/virtualization/#virtualization-bhyve-prep
> [1] https://lists.freebsd.org/archives/freebsd-wireless/2025-July/003577.html
>