MAC address flapping occurs on a network when the network has a loop or is attacked. To prevent MAC address flapping, you can set MAC address learning priorities for interfaces so that MAC addresses can be learned by correct interfaces. When the same MAC address is learned by interfaces with different priorities, the MAC address entry learned by the interface with the highest priority overrides the MAC address entries learned by other interfaces. You can also determine whether to allow MAC address flapping between interfaces with the same priority.
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