Method and apparatus for keeping network address translation mapping alive

An apparatus for keeping network address translation mapping alive, wherein the apparatus is applied to a network address translation (NAT) device and comprises:

• a memory and a processor,
• the memory stores a computer readable program;
• and
• the processor runs the program in the memory to implement the following method:
• receiving a probe request sent by an internal network device, wherein the probe request comprises a private network address of the internal network device;
• sending a probe response to the internal network device, wherein the probe response carries indication information, and the indication information indicates that the internal network device does not actively initiate a heartbeat message to keep network address translation mapping alive;
• and
• allocating at least two public network addresses to the internal network device from idle public network addresses comprised in an address resource pool, and
• mapping a private network address of the internal network device to a current active address, using one of the at least two public network addresses as the current active address in each time period of a subsequent session process between the internal network device and an external network device, including cyclically performing the following operations in sequence for the at least two public network addresses based on a sequence of configuring the at least two public network addresses:
• (a) starting a timing process in response to selecting a current public network address until a timing duration reaches a timeout duration associated with the public network address, and
• (b) using the selected current public network address as the current active address in a current timing process, wherein one public network address is associated with one piece of the timeout duration;
• receiving a first data report message sent by the internal network device to the external network device, wherein a source address in the first data report message is the private network address of the internal network device;
• replacing the private network address of the internal network device in the first data report message with a first address that serves as the current active address;
• and
• sending the first data report message to the external network device.