2. Network model (for the sustainable development of the network) The network model includes the OSI reference model and the TCP/IP reference model OSI model: local area network;
3. LAN
Network cable-crystal head-pointer ordering is the rule
*IP address can be bound to mac address
192.168.0.23 - 192.168.0.140 - preferably make sure they walk a short distance between them
*The switch can also realize the function of routing
* Layer 3 switch - brings the function of routing
*OSI reference model, only to establish a reference standard for realizing network interaction
*The TCP/IP reference model is a simplification of the OSI reference model
socket belongs to session layer
*http is based on tcp data transmission
*UDP data transmission is insecure, and it cannot be guaranteed whether the other party receives it or not.