Private Networks Private Networks define subnets that are protected. A Private Network is defined by the NIC the network is connected to and the IP addresses ranges. Private Networks can be used as sources and destinations in any rules. If no NIC is specified for a Private Network, the network is considered as non-existing and is not taken into account in rules. Private Network should be used to define your local subnets, Perimeter Networks (aka DMZ), connected via VPN or Dialup networks.