IP Defined address :
1,IP An address is used to identify a node in a network ( Or network device interface );
2,IP Addresses are also used for IP Addressing of packets in networks ;
3, One IPv4 Address right 32 position , Usually used “ dotted decimal ” express .

Binary , decimal system , The conversion relationship between hexadecimal three

IP Category of address
IPv4 All in all :2^32=4,294,967,296 individual

( be careful !!!:127 The address is tested as a local loopback , To test the TCP/IP Is it normal )

IP The address is determined by the network part , The host part consists of these two parts .
give an example :

If there is an express , From Huawei base in Shenzhen , Send to a specific place in a district of Shanghai . Express companies in Shenzhen don't care which specific location to send to Shanghai , Just send it to Shanghai . here , This area of Shanghai is equivalent to
Area number ( The network part ) The address of the city is equivalent to that of Shanghai ( That is, the host part ) In network devices , Routing device “ Only care ” network number .

IP Address , How to distinguish between network part and host part

NetMask Netmask ( Equivalent to green leaves )
The netmask is 32bits, And IP The number of digits in the address is the same
The network mask subbinary representation is represented by the 0,1 Constitutive
The value is 1 Of bit corresponding IP Network bit of address ; The value is 0 Of bit corresponding IP Host bit in address , To help identify a IP Network bit and host bit of address .

IP Communication network type
unicast , radio broadcast , Multicast

IP Address type

Variable length subnet mask (VLSM)
Why divide subnets ?