Ap_isolate behavior.

[Sergey Ryazanov]

On Fri, Sep 10, 2021 at 10:42 AM Johannes Berg
<johannes at sipsolutions.net> wrote:
> On Thu, 2021-09-09 at 19:58 -0400, Mark K Vallevand wrote:
>> I've been looking at the kernel sources, and it should behave correctly when ap_isolate=1.
>> I suspect that it might be some networking thing that I don't understand or have mis-configured.
>> What I have is an ethernet bridge with wi-fi and ethernet slaves.  The bridge is used for some packet inspection and to get traffic into our solution.
>> When I have 2 stations connected to wi-fi and ap_isolate=0, the stations can talk to each other, and I can see their traffic using tcpdump on the wi-fi interface.  I do not see their traffic on the bridge.  So, aha I say.  Set ap_isolate=1.
>
> IIRC you shouldn't see the traffic on the wifi interface if it's added
> to the bridge correctly?

It depends on what you mean when saying "see". TCP/IP stack will not
see any packets because the bridge will redirect the normal data path
by installing the rx handler on the slave (e.g. wireless) interface.
On the other hand, pcap (tcpdump) will perfectly reveal to us what
packets travel across the interface boundary.

-- 
Sergey