There are two types of IP addresses : Classless and classful. Classful IP addresses are the IP addresses that subnet masks are defined due to IP address interval. There are three types of IP Address Classes : A, B and C
Class A IP Address
•When written in a binary format, the first (leftmost) bit of a Class A address is always 0.
•Example of a Class A IP address is 124.95.44.15.
•The first octet, 124, identifies the network number assigned by ARIN which will range from 0-126.
(127 does start with a 0 bit, but has been reserved for special purposes.)
•The internal administrators of the network assign the remaining 24 bits
•All Class A IP addresses use only the first 8 bits to identify the network part of the address.
•Every network that uses a Class A IP address can have assigned up to 2 to-the-power of 24 (224)
(minus 2), or 16,777,214, possible IP addresses to devices that are attached to its network
Class B IP Address
•The first 2 bits of a Class B address are always 10 (one and zero).
•Example of a Class B IP address is 151.10.13.28
•The first two octets identify the network number assigned by ARIN•Class B IP addresses always have values ranging from 128 to 191 in their first octet•Every network that uses a Class B IP address can have assigned up to 2 to-the-power of 16 (216) (minus 2 again!), or 65,534, possible IP addresses to devices that are attached to its network
Class C IP Address
•The first 3 bits of a Class C address are always 110 (one, one and zero).
•An example of a Class C IP address is 201.110.213.28
•The first three octets identify the network number.
•Class C IP addresses always have values ranging from 192 to 223 in their first octet.
•All Class C IP addresses use the first 24 bits to identify the network part of the address
•Every network that uses a Class C IP address can have assigned up to 28 (minus 2), or 254, possible IP addresses to devices that are attached to its network
