A method and an apparatus for cross-service-zone communication, and a data center network. When a first virtual machine in a server sends a packet to a second virtual machine, the server determines, through searching, whether a routing table of a tenant to which the first virtual machine belongs exists on the server; when the routing table of the tenant to which the first virtual machine belongs does not exist on the server, send the packet to a gateway; receive the routing table of the tenant to which the first virtual machine belongs sent by the gateway through a service zone manager; and forward a subsequent packet of the first virtual machine according to the routing table; where the first virtual machine and the second virtual machine are located in different service zones.