Address Allocation Method, CGN Device, and CGN Dual-Active System

An address allocation method, comprising:

• receiving, by a second carrier grade network address translation (CGN) device, a first to-be-sent packet sent by a network address translation (NAT) device;
• searching a recorded correspondence between a private network address, a public network address, and a port range for a public network address and a port range that are correspondingly allocated to a source address of the first to-be-sent packet;
• sending, by the second CGN device, an address allocation request to a first CGN device based on a search result indicating that the public network address and the port range that are correspondingly allocated to the source address of the first to-be-sent packet are not in the correspondence, wherein the address allocation request comprises the source address of the first to-be-sent packet;
• and
• receiving a correspondence sent by the first CGN device and between the source address of the first to-be-sent packet, the public network address, and the port range,
• wherein the first CGN device is preset in a CGN dual-active scenario and configured to allocate a public network address and a port range to a private network address, and
• wherein the second CGN device is preset in the CGN dual-active scenario and not configured to allocate the public network address and the port range to the private network address.

A carrier grade network address translation (CGN) device that is used as a first CGN device, comprising:

• a network interface configured to receive an address allocation request sent by a second CGN device, wherein the address allocation request comprises a first private network address;
• a memory comprising instructions;
• and
• one or more processors in communication with the memory and execute the instructions to:
• search a recorded correspondence between a private network address, a public network address, and a port range for the first private network address received by the network interface;
• allocate a public network address and a port range to the first private network address based on a search result indicating that the first private network address is not in the correspondence;
• record a correspondence between the first private network address, the allocated public network address, and the allocated port range,
• wherein the network interface is further configured to synchronize, to the second CGN device, the correspondence between the first private network address, the public network address allocated by the one or more processors, and the port range allocated by the one or more processors,
• wherein the CGN device is preset in a CGN dual-active scenario and configured to allocate a public network address and a port range to a private network address, and
• wherein the second CGN device is preset in the CGN dual-active scenario and not configured to allocate the public network address and the port range to the private network address.

A carrier grade network address translation (CGN) device that is used as a second CGN device, comprising:

• a network interface configured to receive a first to-be-sent packet sent by a network address translation (NAT) device;
• a memory comprising instructions;
• and
• one or more processors in communication with the memory and execute the instructions to search a recorded correspondence between a private network address, a public network address, and a port range for a public network address and a port range that are correspondingly allocated to a source address of the first to-be-sent packet received by the network interface, and
• wherein the network interface is further configured to:
• send an address allocation request to a first CGN device based on a search result indicating that the public network address and the port range that are correspondingly allocated to the source address of the first to-be-sent packet are not in the correspondence, wherein the search result is obtained by the one or more processors, and wherein the address allocation request comprises the source address of the first to-be-sent packet;
• and
• receive a correspondence between the source address of the first to-be-sent packet, the public network address, and the port range, wherein the correspondence is sent by the first CGN device for the address allocation request sent by the network interface, wherein the first CGN device is preset in a CGN dual-active scenario and configured to allocate a public network address and a port range to a private network address, and wherein the CGN device is preset in the CGN dual-active scenario and not configured to allocate the public network address and the port range to the private network address.