IP Adresses Classes and Ranges
Class A
Subnet Mask
255.0.0.0
Class B
Subnet Mask
255.255.0.0
Class C
Subnet Mask
255.255.255.0
Class A
Starting IP
0.0.0.0
Class A
Private Starting IP
10.0.0.0
Class A
Private Ending IP
10.255.255.255
Class B
Starting IP
128.0.0.0
Class B
Private Starting IP
172.16.0.0
Class B
Private Ending IP
172.31.255.255
Class C
Starting IP
192.0.0.0
Class C
Private Starting IP
192.168.0.0
Class C
Private Ending IP
192.168.255.255
Class D
Starting IP
224.0.0.0
Class E
Starting IP
240.0.0.0
Class B
Private First Octet
172
Class B
Private Second Octet Start
16
Class B
Private Second Octet End
31
Class C
Private First Octet
192
Class C
Private Second Octet
168
Class A
Private First Octet
10