Re: How to Autoconnect Two WiFi Cards?

[James Prestwood <prestwoj@gmail.com>]

Hi Fabian,

On 1/23/24 5:36 AM, Fabian Herb wrote:
> Hi James,
>
>> Am 18.01.2024 um 13:18 schrieb James Prestwood <prestwoj@gmail.com>:
>>
>> On 1/18/24 3:51 AM, Fabian Herb wrote:
>>>> Without implementing a new feature with per-phy profiles about the only thing you could do would be:
>>>>
>>>>   - Create a network namespace (e.g. ns0)
>>> Thanks! I’ll look into that idea. At a first glance it looks quite cumbersome though. Maybe this could be done with LXC or Docker...
>> Yeah I actually hesitated to even suggest it :) Though once you've done it its not _that_ bad. We do this in our autotests framework to simulate networks, and run multiple instances of IWD. You may be able to do it with a container as well.
> I tried with systemd-nspawn, but that didn't work so well. For one you can’t put the phy into the container with the provided tools because it’s not a regular network interface (setting the ns manually works though). And also starting iwd inside the container gives me a „Module rfkill failed to start: -2“, even if I bind /dev/rfkill into the container…
I only ever did this with low level namespaces, but yeah, its a quirky 
setup to achieve what you want.
>
> I’m starting to think that it might be easier to add a feature to iwd that does what I want :). But I’m still a bit lost in the source code.
>
>>>> What exactly are you trying to accomplish by connecting to separate SSID’s?
>>> That’s for redundancy. The machine is moving around quite a bit, so there’s lots of roaming. Reception can be bad in some areas. And with two WiFi connections and 802.11r Fast Transition if possible, I hope to get network interruptions close to zero. Redundancy itself is done on application level.
>> So this very same thing is being added in WiFi 7, called Multi-Link Operation (MLO). It doesn't help you now as IWD doesn't have any logic for it but just putting it out there (and maybe AP support is also needed). They've been working on this feature in the kernel for quite some time now.
> Yes, WiFi 7 is certainly interesting. You can already buy WiFi-7-capable hardware now. UniFi promises MLO support to be available in February with a firmware update for example.
>
> Is there a time frame when MLO support might be added to iwd? Or is the work on kernel support still ongoing?

It very much seems like its in active development in the 
kernel/wpa_supplicant. There time-frame to add it to IWD but at the very 
least we'd want the kernel support to be stable. Another factor to 
adding larger features, simply put, is corporate agendas. Unfortunately, 
gone are the days of us IWD devs getting paid to add whatever we want, 
whenever we want (that's at least my situation).

So as for MLO yes I could see it being added at some point, but its not 
really a priority. My company is just now starting to add WiFi 6e. When 
WiFi 7 becomes more widespread I could probably get MLO support on the 
agenda as it seems like it would add connection reliability but I won't 
lie, its a long way off. Anyone else is welcome to implement before then 
though :)

Thanks,

James

>
> Best regards,
> Fabian
>