fwknop implements network access controls (via iptables) based on a flexible port knocking mini-language, but with a twist; it combines port knocking and passive operating system fingerprinting to make it possible to do things like only allow, say, Linux-2.4/2.6 systems to connect to your SSH daemon GUI:Нет Терминал:Есть Windows альтернатива : Программные требования : Аппаратные требования :