Linux Ethernet Bridging - Mar 2018 - [Bridge] Problem with bridge (mcast-to-ucast + hairpin) and Broadcom's 802.11f in their FullMAC fw

On Tue, Feb 27, 2018 at 11:08:20AM +0100, Rafa? Mi?ecki
wrote:
> I've problem when using OpenWrt/LEDE on a home router with
Broadcom's
> FullMAC WiFi chipset.
Hi Rafa?,

Thanks for reporting this issue!
> Can you see any solution for this problem? Is that an option to stop
> multicast-to-unicast from touching 802.11f packets? Some other ideas?
> Obviously I can't modify Broadcom's firmware and drop that
obsoleted
> standard.
Just to avoid some potential confusion: This is more an issue of
hairpinning than it is an issue of multicast-to-unicast per se,
right?

That is, if you set this to 0 manually:
/sys/class/net/<ap-iface>/brport/multicast_to_unicast
Then the issue still occurs, right?

Regards, Linus

On Mon, Mar 12, 2018 at 12:08:56PM +0100, Linus L?ssing
wrote:
> On Tue, Feb 27, 2018 at 11:08:20AM +0100, Rafa? Mi?ecki wrote:
> > I've problem when using OpenWrt/LEDE on a home router with
Broadcom's
> > FullMAC WiFi chipset.
> 
> Hi Rafa?,
> 
> Thanks for reporting this issue!
> 
> > Can you see any solution for this problem? Is that an option to stop
> > multicast-to-unicast from touching 802.11f packets? Some other ideas?
> > Obviously I can't modify Broadcom's firmware and drop that
obsoleted
> > standard.
> 
> Just to avoid some potential confusion: This is more an issue of
> hairpinning than it is an issue of multicast-to-unicast per se,
> right?
> 
> That is, if you set this to 0 manually:
> /sys/class/net/<ap-iface>/brport/multicast_to_unicast
> Then the issue still occurs, right?
Btw., if in OpenWRT/LEDE you set 'option multicast_to_unicast 0'
in /etc/config/network for the bridge (and not bridge port)
then netifd should refrain from setting the bridge hairpinning and
AP isolation on wireless devices, too, if I remember correctly.

Can you confirm that the issue disappears for you then?

On 12 March 2018 at 12:08, Linus L?ssing <linus.luessing at c0d3.blue>
wrote:
> On Tue, Feb 27, 2018 at 11:08:20AM +0100, Rafa? Mi?ecki wrote:
>> I've problem when using OpenWrt/LEDE on a home router with
Broadcom's
>> FullMAC WiFi chipset.
>
> Hi Rafa?,
>
> Thanks for reporting this issue!
>
>> Can you see any solution for this problem? Is that an option to stop
>> multicast-to-unicast from touching 802.11f packets? Some other ideas?
>> Obviously I can't modify Broadcom's firmware and drop that
obsoleted
>> standard.
>
> Just to avoid some potential confusion: This is more an issue of
> hairpinning than it is an issue of multicast-to-unicast per se,
> right?
>
> That is, if you set this to 0 manually:
> /sys/class/net/<ap-iface>/brport/multicast_to_unicast
> Then the issue still occurs, right?
I can't really tell, I didn't go into details on bridge +
mcast-to-unicast + hairpin.

By default OpenWrt/LEDE sets
/sys/class/net/<ap-iface>/brport/multicast_to_unicast
to 1. Changing it to 0 (with a simple echo) doesn't /fix/ the problem.

-- 
Rafa?