Network knowledge starts from zero One: private address.

Class A private address network segment:

10.0.0.0-10.255.255.255

Reserved address:

127.0.0.0-127.255.255.255 for cyclic testing

Commonly referred to as the 127.0.0.1 loopback address, in fact, this is not true, the other within the scope of the address can also do loopback address.

Class B Private Address network segment:

172.16.0.0-172.31.255.255

Reserved address:

169.254.0.0 to 169.254.255.255 is a reserved address. If your IP address is automatically getting an IP address, and you don't find a DHCP server available on the network, you'll get an IP address temporarily from 169.254.0.1 to 169.254.255.254 (which I don't understand).

Class C Private Address network segment:

192.168.0.0-192.168.255.255

The private address needs to be translated by a NAT network address on the public network.

Network knowledge starts from zero One: private address.