This module protects your server from unapproved access from networks by means of closing or opening required ports for certain services at your server specified interfaces.
This module uses system tool iptables that serve as default interface of firewall netfilter for Linux kernels. A user-friendly web interface hides command line of iptables interface and does not require any specific knowledge to manage the firewall.
For example if all incoming connections are closed by default, to open ssh access to your server from local network you need to add one row to rules table to open ssh port using web interface for the \"internal\" interface. If all incoming connections are opened by default then you need to close ssh for the \"external\" interfaces.
Pic.: Proxy server closed ports