Flooded traffic

Broadcast and multicast packets will always use the same path between the source and destination edge switches unless link failures create the need to select new paths. (Broadcast and multicast traffic entering the mesh from different edge switches are likely to take different paths.) When an edge switch receives a broadcast from a non-mesh port, it floods the broadcast out all its other non-mesh ports, but sends the broadcast out only those ports in the mesh that represent the path from that edge switch through the mesh domain. (Only one copy of the broadcast packet gets to each edge switch for broadcast out of its non-meshed ports. This helps to keep the latency for these packets to each switch as low as possible.)

A broadcast path through a switch mesh domain

Any mesh switches that are not edge switches will flood the broadcast packets only through ports (paths) that link to separate edge switches in the controlled broadcast tree. The edge switches that receive the broadcast will flood the broadcast out all non-meshed ports. Some variations on broadcast/multicast traffic patterns, including the situation where multiple VLANs are configured and a broadcast path through the mesh domain leads only to ports that are in the same VLAN as the device originating the broadcast.