The range of IPV4 address classification and network number is as follows:
Class A address
(1) The first byte of a class A address is the network address, and the other 3 bytes are the host address.
(2) Class A address range: 1.0.0.1—126.255.255.254
(3) Private addresses and reserved addresses in Class A addresses: ① 10.XXX is the private address range (10.0.0.0-10.255.255.255) ② 127.XXX is the reserved address, which is used for loop testing.
Class B address
(1) The first byte and the second byte of the class B address are the network address, and the other two bytes are the host address.
(2) Class B address range: 128.0.0.1—191.255.255.254.
(3) Private addresses and reserved addresses of class B addresses: ① 172.16.0.0—172.31.255.255 are private addresses ② 169.254.XX are reserved addresses. If your IP address is to obtain an IP address automatically,
And you can't find a DHCP server available on the network. will get one of the IPs.
Class C address
(1) The first byte, the second byte and the third byte of the C class address are the network address, and the fourth byte is the host address. In addition, the first three bits of the first byte are fixed to 110.
(2) Class C address range: 192.0.0.1—223.255.255.254.
(3) Private addresses in Class C addresses: 192.168.XX is a private address. (192.168.0.0-192.168.255.255)
Class D address
(1) Class D addresses are not divided into network addresses and host addresses, and the first four bits of the first byte are fixed at 1110.
(2) Class D address range: 224.0.0.1—239.255.255.254
Class E address
(1) Class E address does not distinguish between network address and host address, and the first five bits of its first byte are fixed as 11110.
(2) Class E address range: 240.0.0.1—255.255.255.254