A method for synchronizing virtual machine location information between data center gateways, a gateway, and a system, where a second gateway of a second data center receives a first location update message from a first gateway of a first data center, where the first location update message notifies that location information of the first virtual machine is changed. The second gateway deletes, according to the first location update message, a media access control (MAC) route of the first virtual machine saved in the second gateway, and the second gateway learns, from the first virtual machine to obtain current location information of the first virtual machine when the second gateway receives a packet destined for the first virtual machine and the second gateway does not save the MAC route of the first virtual machine.