Re: [PATCH RFC net-next 3/3] net: dsa: deny 8021q uppers on vlan unaware bridged ports
From: Vladimir Oltean
Date: Tue Nov 11 2025 - 06:59:43 EST
On Tue, Nov 11, 2025 at 11:06:48AM +0100, Jonas Gorski wrote:
> But I noticed while testing that apparently b53 in filtering=0 mode
> does not forward any tagged traffic (and I think I know why ...).
>
> Is there a way to ask for a replay of the fdb (static) entries? To fix
> this for older switches, we need to disable 802.1q mode, but this also
> switches the ARL from IVL to SVL, which changes the hashing, and would
> break any existing entries. So we need to flush the ARL before
> toggling 802.1q mode, and then reprogram any static entries.
I'm not clear on what happens. "Broken" FDB entries in the incorrect
bridge vlan_filtering mode sounds like normal behaviour (FDB entries
with VID=0 while vlan_filtering=1, or FDB entries with VID!=0 while
vlan_filtering=0). They should just sit idle in the ARL until the VLAN
filtering mode makes them active.