liuweifei
1. Classification of IP address:
Class A IP address Class A IP address consists of a 1-byte network address and a 3-byte host address. The highest bit of the network address must be "0". The address range is from 1.0.0.1 to 127.255.255.254 (binary representation is: 00000001 00000000 00000000 00000001-01111111 11111111 11111111 11111110). The last one is the broadcast address.
Class B IP address Class B IP address consists of a 2-byte network address and a 2-byte host address. The highest bit of the network address must be "10". The address range is from 128.0.0.1-191.255.255.254 (in binary format: 10000000 00000000 00000000 00000001-10111111 11111111 11111111 11111110). The last one is the broadcast address.
Class C IP addresses range from 192.0.0.1-223.255.255.254 (binary representation: 11000000 00000000 00000000 00000001-11011111 11111111 11111111 11111110). The last one is the broadcast address.
2. Familiar with the conversion between decimal and binary
10.1.1.1 ----- 00001010.00000001.00000001.00000001
10.1.1.2 ----- 00001010.00000001.00000001.00000010
10.1.1.3 ----- 00001010.00000001.00000001.00000011
10.1.1.4 ----- 00001010.00000001.00000001.00000100
10.1.1.5 ----- 00001010.00000001.00000001.00000101
255.255.255.0 ---- 11111111.11111111.11111111.00000000
3. The role of the subnet mask: define the size of the network and mark the scope of the network