ipnat opens the filename given (treating "-" as stdin) and parses the
file for a set of rules which are to be added or removed from the IP NAT.
Each rule processed by ipnat
is added to the kernels internal lists if there are no parsing problems.
Rules are added to the end of the internal lists, matching the order in
which they appear when given to ipnat.
Note that if
is not enabled when NAT is configured, it will be enabled
automatically, as the same kernel facilities are used for
NAT functionality. In addition, packet forwarding must be