1, identification port: from 0 to 1023, used to bind common services.

2. Registration ports: from 1024 to 49 15 1, used to bind services. Binding is not fixed and can be used for other purposes.

3. Dynamic ports: From 49 152 to 65535, theoretically, ports should not be allocated for services. In fact, the machine allocates dynamic ports from 1024.