One notation for describing a network range is “CIDR”:- it lists an address on the network, followed by a forward slash and the number of bits in the address that describe the network. Some examples:
The private Class A network is 10.0.0.0/8
The private 16 x Class B networks is 172.16.0.0/12
The private 256 x Class C networks is 192.168.0.0/16
As a side note, in situations where network notation is required and a single address is not allowed, the notation can still be used to specify a single address. Use the notation:- 192.168.50.100/32. This specifies that all 32 bits of the address form the network. This is not relevant to the firewall generated by this program, but is a useful tidbit of information.