Category of IP address

We know more and more IP By using , It's not just a computer at home , It also includes television , Smart home and so on have been assigned to belong to them IP, Which means , More and more IP By using , However, the most widely used is already very mature IPV4 Address . It is because of IP Addresses are more and more widely used , In order to prevent IP Not enough use , Now there is IPV6.

IPV4 And IPV6 The difference between

IPV4 from 32 Bit binary structure , It is expressed in dotted decimal ;

IPV6 from 128 Bit binary structure , It is expressed in decimal system .

 IP Address components

IP The address consists of network bit and host bit , The network bits are the same , Means in a broadcast domain , In a broadcast domain , Use the host bit to distinguish different hosts . Subnet mask to distinguish between network bits and host bits , The mask consists of consecutive 0 and 1 form , among 1 On behalf of network bit ,0 Represents the host bit .

Five category IP Address

IP The address is divided into A、B、C、D、E Five category , The specific classification rules are as follows ：

A：0XXX XXXX （1-126）

B：10XX XXXX （128-191）

C：110X XXXX （192-223）

D：1110 XXXX （224-239）

E：1111 XXXX （240-255）

among ：

A、B、C Class is unicast address , It can be used as a source IP Address , It can also be a goal IP Address

A：255.0.0.0 Big net

B：255.255.0.0 Medium network

C：255.255.255.0 Small network

But now we usually use C class IP Address . At present, there is no specific classification IP, We now directly put what we use IP It's called no category IP.

D Class is multicast address , Only as a target IP Address using , Cannot be used as a source IP Use

E Class is reserved address

special IP Address

1、 Loopback address ：127.0.0.1 - 127.255.255.254

2、 Restricted broadcast address ：255.255.255.255 , It can only be used as a target IP Use

3、 All the hosts 1 The address of ：192.168.1.255/24, Is the direct broadcast address , It can only be used as a target IP Address using

4、 All the hosts 0 The address of ：192.168.1.0/24 , Network segment （ network address , network number ）

5、0.0.0.0 Express ： It can mean that there is no IP Address can also mean all IP Address

6、 Local link address / Automatic private address ：169.254.0.0/16