Connection Tracing table

Connection Tracing table
It records the source and destination IP addresses before modification, and the modified source and destination IP addresses, and stores them in a hash structure.
When a data packet comes over, both the Internet and Intranet cannot escape the above two situations. If it does not belong to the above two situations, it must not be the content in the table.
If a table is found, the converted data is automatically retrieved.
The converted data comes in, automatically changes to the data before conversion, and is sent out.
The data before conversion is automatically converted and sent out.

 

The status detection function in iptables is implemented by the State option.