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Issues when moving to another wlan on the same AP but on another wifi chip #7

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Hello,

I am running three Asus AX4200 with openwrt master ( self compiled ). All AX4200 basically run as dumb access points. I have mutliple BSSIDs
running, using the same names on 5 GHz and 2,4 GHz, to allow for ongoing connection (fall back from 5HGz to 2,4 GHz) when moving away from the AP. And I am runnig different Service Sets for different authentications, as I am using both pre-shared keys and EAP authentication.

I see an issue in the following scenario:

  • client (iPhone) is connected to a wifi network on 5 GHz. Bridger is enabled. I see offloading , all fine
  • the client then is connected to a 2,4 Ghz wifi on the same AP. 5GHz and 2,4 GHz use different Chips ( and thus, different bridge ports ? ) on the AX4200, likely on most wifi routers.
  • when changing wifi from a 5 GHz to a 2,4 GHz network on the iphone, speed goes down ( in iperf to 0 ) when bridger is enabled. As far as I can tell
    from bridge show and brctl command outputs, the iPhones MAC address is associated to the new port immediately. When stopping
    the bridger service, speed immediately recovers to expected levels. Without bridger enabled at all, moving between wifi networks
    works fine.
  • Changing from one wifi at 5 GHz to another wifi with 5 Ghz ( and thus on the same chip) does not cause issues.

While testing, change of wlans is done by hand, but as described above, leaving a 5GHz BSSID and connecting automatically to a 2,4 GHz BSSID
is expected and wanted behaviour.

To me, it looks like bridger puts in some "shortcut rules" for offloading, but it misses the port change of a mac address when the client moves over to
another wlan on the other wifi chip, so packets possibly are attempted to be forwarded to the old port and never reach the client after it moved to another wifi chip.

Is there some way to check the entries bridger puts into the forwarding path, or is there any configuration option that causes bridger to detect the change and adopt to them? Or is it in the end not a bridger issue at all?

Regards,
Stephan

(edit: fixed some typos)

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