IPv4 address

1.IPV4 Address Overview

1. Concept

Concept ： It is unique in the world to assign one to each interface of each host on the Internet 32 Bit representation

2. Representation ： dotted decimal

32 position IPV4 The address is not easy to read 、 Record and input , Dot decimal notation is used for user convenience
eg：

3. Classified addressed IPv4 Address

• Only A class 、B Classes and C Class addresses can be assigned to the interfaces of hosts or routers in the network
• Host number by “ whole 0” Your address is the network address , Interfaces that cannot be assigned to a host or router
• The host number is “ whole 1” Your address is the broadcast address , Interfaces that cannot be assigned to a host or router

1. Yes A Class address specific analysis
   

2. Yes B Analysis of class address
   

3. Yes C Analysis of class address
   

4. A little exercise ： If you can , It shows that you have almost mastered
   

4. The of dividing subnets IPv4 Address

1. Subnet mask ：32 Bit subnet mask can indicate classification IP Address of the Host number part Borrowed a few bits as the subnet number ,1 Corresponding network number and subnet number ,0 Corresponding host number
   
2. An example
   
   
3. An exercise
   
4. Default subnet mask
   Refers to the subnet mask used when the subnet is not divided
   

5. Without classification IPv4 Address

The division of subnets alleviates the difficulties encountered in the development of the Internet to a certain extent , But a huge number C Class network is not fully used because its address space is too small , And the Internet IP Address consumption is still accelerating , Whole IPv4 The address space is threatened to be completely exhausted . So , Internet Engineering Task Force IETF It also puts forward the method of non classification addressing to solve IP The problem of address tension , At the same time, it also specially established IPv6 The working group is responsible for studying the new version IP In order to completely solve IP Address exhaustion problem .

1. CIRD Use the slash method
   
   
   practice ：