A cloud computing data center system includes a first server, a second server, a cloud management platform, and a switch. The first server includes a first computing node and a first distributed gateway. The first distributed gateway receives a management packet sent by the cloud management platform. The first distributed gateway records network information of the second VLAN. A first virtual machine sends a first service packet that carries service data to a second virtual machine. The first distributed gateway receives the first service packet, generates a second service packet by modifying the first service packet based on the network information of the second VLAN, and sends the second service packet to the switch. A second distributed gateway receives the second service packet forwarded by the switch, and sends the second service packet to the second virtual machine. In this way, network reliability may be improved.