Ipq806x DSA Switch and AX3600 Switch problem

Hi !

Please let me describe the following situation. I have a network with 2 access points.
AP1: Buffalo WZR-HP-AG300H with swconfig
AP2: Zyxel NBG6817 with DSA/Xiaomi AX3600 with NSS switch

A smartphone associates with access point AP 1.

|----|AP 1|--Smartphone
|----|AP 2|--
The smartphone sends a DHCP request, this results in the following fdbs:
The switch in AP 1 has the following fdb:
CPU-Port: Smartphone MAC

The switch in AP 2 has the following fdb:
Port1 : Smartphone MAC

2. The device moves to the location of AP 2, it roams.
|----|AP 1|
|----|AP 2|--Smartphone
The switch in AP 1 has the following fdb (has not received an update):
CPU-Port: Smartphone MAC (is OK in that moment, will update later)

The switch in AP 2 has the following fdb:
Port1 : Smartphone MAC (is wrong)
Should be:
CPU-Port: Smartphone MAC

Let me explain step by step:
*The smartphone associates with AP 2
*The smartphone send a DHCP broadcast
*The internal linux bridge updates its fdb, the smartphone mac now points to the wireless interface.
*The switch sees the smartphone MAC on the CPU port, but it does not update the fdb!
*The incoming DHCP reply is discarded by the switch. The smartphone is therefore unreachable.
*The fdb aging timer clears the smartphone MAC in the fdb. (180s)
*The incoming DHCP reply is forward by the switch to the CPU port. The smartphone is reachable.

On the ax3600 I can flush the switch fdb with 'ssdk_sh fdb entry flush 1'. This helps immediately.
On ipq806x with zyxel_nbg6817, I do not know a way to flush the DSA fdb. bridge fdb del ... does not work.

Of course, this is only a quick fix. A correct fix would be to allow the DSA and NSS switch to learn correctly from the CPU port.

I think there is already a solution for marvell:

But this is a completely different driver.

This should be kept in mind for further DSA migration steps.

Kind regards.

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I found a solution for the proposed dsa switch on the ipq806x platform. I already created a pull request.

Perhaps also other platforms are affected and miss the assisted learning feature. It is introduced here::

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This fixes the problem only partial on ipq806x and introduces more problems..

That same issue seems to be discussed here: Roaming Issues Xiaomi AX3600