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Date: Tue, 1 Dec 2020 09:49:17 +0100 From: Peter Vollmer <peter.vollmer@...il.com> To: Tobias Waldekranz <tobias@...dekranz.com> Cc: Andrew Lunn <andrew@...n.ch>, Network Development <netdev@...r.kernel.org> Subject: Re: dsa/mv88e6xxx: leaking packets on MV88E6341 switch On Thu, Nov 26, 2020 at 10:41:44PM +0100, Tobias Waldekranz wrote: > On Wed, Nov 25, 2020 at 15:09, Peter Vollmer <peter.vollmer@...il.com> wrote: > > - pinging from client0 (connected to lan0 ) to the bridge IP, the ping > > requests (only the requests) are also seen on client1 connected to > > lan1 > > This is the expected behavior of the current implementation I am > afraid. It stems from the fact that the CPU responds to the echo request > (or to any other request for that matter) with a FROM_CPU. This means > that no learning takes place, and the SA of br0 will thus never reach > the switch's FDB. So while client0 knows the MAC of br0, the switch > (very counter-intuitively) does not. > > The result is that the unicast echo request sent by client0 is flooded > as unknown unicast by the switch. This way it reaches the CPU but also, > as you have discovered, all other ports that allow unknown unicast to > egress. > Thanks for this explanation. Would there be a way to inject the br0 MAC into the switch FDB using 'bridge fdb' or some other tool as a workaround ? And is this behaviour the same with all other DSA capable switches (or at least the mv88e6xxx ones)? Will this change eventually after the implementation is complete ? Thanks and best regards Peter
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