A source Medium Access Control (MAC) address is learned upon receiving a data message from a local network, and a learned local MAC address entry is added to a MAC address forwarding table. A source MAC address is not learned upon receiving a data message from a tunnel. When a local MAC address entry in the MAC address forwarding table changes, a synchronization message is sent via each tunnel associated with a Virtual Extensible Local Area Network (VXLAN) in the changed local MAC address entry, and is saved into a database corresponding to the tunnel. Each tunnel corresponds to one database.