Messages in this thread | | | Date | Mon, 2 Aug 2021 16:07:23 +0300 | From | Vladimir Oltean <> | Subject | Re: [RFC net-next v2 1/4] net: dsa: mt7530: enable assisted learning on CPU port |
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On Sun, Aug 01, 2021 at 03:10:19AM +0800, DENG Qingfang wrote: > Consider the following bridge configuration, where bond0 is not > offloaded: > > +-- br0 --+ > / / | \ > / / | \ > / | | bond0 > / | | / \ > swp0 swp1 swp2 swp3 swp4 > . . . > . . . > A B C > > Address learning is enabled on offloaded ports (swp0~2) and the CPU > port, so when client A sends a packet to C, the following will happen: > > 1. The switch learns that client A can be reached at swp0. > 2. The switch probably already knows that client C can be reached at the > CPU port, so it forwards the packet to the CPU. > 3. The bridge core knows client C can be reached at bond0, so it > forwards the packet back to the switch. > 4. The switch learns that client A can be reached at the CPU port. > 5. The switch forwards the packet to either swp3 or swp4, according to > the packet's tag. > > That makes client A's MAC address flap between swp0 and the CPU port. If > client B sends a packet to A, it is possible that the packet is > forwarded to the CPU. With offload_fwd_mark = 1, the bridge core won't > forward it back to the switch, resulting in packet loss. > > As we have the assisted_learning_on_cpu_port in DSA core now, enable > that and disable hardware learning on the CPU port. > > Signed-off-by: DENG Qingfang <dqfext@gmail.com> > ---
Reviewed-by: Vladimir Oltean <oltean@gmail.com>
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