The present disclosure discloses a MAC address protection method and switch. A switch in a layer 2 ring network obtains network topology information of the layer 2 ring network, the network topology information includes a protection MAC address of a protected device, an identifier of a switch corresponding to the protection MAC address, and an identifier of each switch in the layer 2 ring network, wherein the protection MAC address is the MAC address of the protected device; and determines a local outgoing interface of the protection MAC address of the protected device according to the network topology information, establishes and stores an outgoing interface of an MAC entry corresponding to the protection MAC address according to the local outgoing interface of the protection MAC address, thereby ensuring the protected device to correctly send and receive messages to meet the topology change of the layer 2 ring network.