Communication method, gateway, and management method and apparatus in hybrid cloud environment

A gateway in a hybrid cloud environment, wherein the gateway is remotely connected to a first subnet of a first data center through a communication tunnel and is connected to a second subnet of a second data center, the first subnet and the second subnet have a same private network segment, the first data center is configured to provide a non-public cloud service, the second data center is configured to provide a public cloud service, and the gateway comprises a processor, a memory, and a communications interface, wherein the memory is configured to store computer-executable instructions, and when the gateway operates, the processor runs the computer-executable instructions in the memory to:

• receive a first address resolution protocol ARP request packet sent by a first device in the first subnet, wherein the first ARP request packet is used to request a MAC address of a second device in the second subnet;
• send a first ARP reply packet to the first device, wherein the first ARP reply packet carries a first MAC address of the gateway;
• and
• obtain and record a first correspondence between a private network address of the second device and the MAC address of the second device in the second subnet.

A management apparatus in a hybrid cloud environment, wherein the hybrid cloud environment comprises a first data center and a second data center, the first data center is configured to provide a non-public cloud service, the second data center is configured to provide a public cloud service, a same private network segment is configured for a first subnet of the first data center and a second subnet of the second data center, and the management apparatus comprising a processor, a memory, and a communications interface, wherein the memory is configured to store computer-executable instructions, and when the management apparatus operates, the processor runs the computer-executable instructions in the memory to:

• create a gateway, wherein the gateway is located in the second data center, the gateway is remotely connected to the first subnet of the first data center through a communication tunnel, and the gateway is connected to the second subnet of the second data center;
• configure the gateway to intercept a first address resolution protocol ARP request packet that is from a first device in the first subnet and that is for a second device in the second subnet, and return a first ARP reply packet to the first device, wherein the first ARP reply packet carries a first MAC address of the gateway;
• and
• configure the gateway to store a correspondence, carried in the first ARP request packet, between an IP address of the first device and a MAC address of the first device.