private+IP+address+spaces

Every network interface that is connected directly to the Internet must have an IP address registered with the Internet Assigned Numbers Authority (IANA), which prevents IP address conflicts between devices. If you are configuring a private network that is not connected to the Internet or one that exists behind a firewall or proxy server, you can configure devices on your network with private addresses and have only the public address configured on the interface that is visible to the Internet.

Each address class configured has a range of private addresses available for general use:

Class A: 10.0.0.0 through 10.255.255.255

Class B: 172.16.0.0 through 172.31.255.255

Class C: 192.168.0.0 through 192.168.255.255

Class A: 1.0.0.1 through 126.255.255.254

Class B: 172.16.0.0 through 172.255.255.254

Class C: 192.168.0.0 through 192.168.254.254

Class D (Reserved for Multicasting Groups): 224.0.0.0 through 239.255.255.255

Class E (Reserved): 240.0.0.0 through 254.255.255.254


 * Class || Network ID || Range of First Octet || Number of Available Network Segments || Number of Available Hosts || Subnet Mask || Leading Bits ||
 * A || W.0.0.0 || 1-126 || 126 || 16,777,214 || 255.0.0.0 || 0 ||
 * B || W.X.0.0 || 128-191 || 16,384 || 65,534 || 255.255.0.0 || 10 ||
 * C || W.X.Y.0 || 192-223 || 2,097,152 || 254 || 255.255.255.0 || 110 ||
 * D (multicasting) || N/A || 224-239 || N/A || N/A || N/A || 1110 ||
 * E (reserved) || W.X.Y.Z || 240-255 || N/A || N/A || N/A || 1111 ||