инструмент администрирования для фильтрации пакетов IPv4 / IPv6 и NAT (administration tool for IPv4/IPv6 packet filtering and NAT)
Диагностика (Diagnostic)
Various error messages are printed to standard error. The exit
code is 0 for correct functioning. Errors which appear to be
caused by invalid or abused command line parameters cause an exit
code of 2, and other errors cause an exit code of 1.
