What are the classifications of IP addresses?

Introduction of IP address: All devices that can access the Internet must have an IP address; And every IP address is equivalent to everyone having a name; Common IP addresses, such as the default address of TP-Link wireless routing: 192.168.1.1 Configure the IP address of your own network card: 192.168.1.2 255.255.0 Note: IP addresses must appear in pairs with subnet masks, otherwise it is meaningless; Check the IP address configuration of your network card: 1. Through the graphical interface (by clicking the mouse)-that is, win system 2. Through the command line # to open the operation, enter cmd and call out the command line window; # Enter the command: ipconfig // Display the IP address information of the network card ipconfig /all -- > View all information of all network cards of the device; Quick Call Run-Start+r; ----------connectivity testing tool-ping; Working principle: 1. Send a request packet -request 2 to the specified target IP address, and the target device returns a reply packet-Reply; For example: ping succeeded! PC>ping 192.168.1.2 Pinging 192.168.1.2 with 32 bytes of data: Reply from 192.168.1.2: bytes=32 time=0ms TTL=128 Reply from 192.168.1.2: bytes=32 ti me=0ms TTL=128 Reply from 192.168.1.2: bytes=32 time=0ms TTL=128 Reply from 192.168.1.2: bytes=32 time=0ms TTL=128 Ping statistics for 192.168.1.2: P ackets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 0ms, Maximum = 0ms, Average = 0 ms--------------for example: ping failed! PC > ping 192.168.1.3 pinging 192.168.1.3 with 32 bytes of data: request timed out. (the default timeout is 2s = 2000 ms) Request timed out. Request timed out. Request t. Imed out. ping statistics for 192.168.1.3: packets: sent = 4, received = 0, lost = 4 (100% loss), shortcut command: press ctrl and C at the same time to quickly terminate the ping command; Special ping command: ping 127.0.0.1 # This address indicates the device itself; # This command indicates that you send a data packet to yourself; If yes, it means that you can receive and send messages normally; Usually use this command to check whether the network card/port function of the device itself is normal!

Classification of IP addresses: (x.x.x.x) Objective: To facilitate the management of IP addresses; Principle: Look at the first few fixed bit； of the first byte in the IP address; 000000000.x.x.x A has the first byte, and the first bit. If it is 0, it is called A 0-127 default mask 255.0.0.0 00000000-> 0 0111 1111-> 127b has the first byte, and the first two bits. Then it is called the default mask of B 128-191 255.0.0 1000 0000-> 128 1011 1111-> the first byte of 191c, and the first three bits. If it is 110, it is called the default mask of C 192-223 255.25.

If you don't understand the bit of IP address, you can ignore it first, and the subnet mask should be remembered synchronously. It is very important to remember that IP address and subnet mask must appear in pairs. This is very important! ! !

Class a address 0-127

Class b address 18-191

Class c address 192-223

Class d addresses 224-255

Class e address 240-255