Linux Network Programming------overview

Provides a perfect and powerful network function.

1, perfect built-in network. The protocol is rich, and the kernel is tight.

2, provide a large number of intenet software.

3, a lot of commands. Complete the file transfer.

4, remote access support.

5. Safe and reliable.

Linux Network model:

Agreement:

Data Link Layer protocol: Ethernet Protocol

Network Layer protocol: IP (Internet Protocol) ICMP (Internetwork Control Message Protocol) ARP (Address Resolution Protocol)

Transport Layer Protocol: TCP (connection-oriented reliable transmission) UDP (non-connected unreliable transport protocol)

Application layer protocol: Telnet File Transfer Protocol (FTP TFTP), Simple File Transfer Protocol (SMTP) and Domain Name Service (DNS) and other protocols.

The packet of the IP protocol is encapsulated by the Ethernet package, the packet of the IP protocol encapsulates the packet of the TCP protocol, the packet of the TCP protocol encapsulates the package of the application layer protocol, the package of the application layer protocol can also encapsulate the package of the application layer protocol, ...

Ethernet Packages:

IP protocol

IP mainly has the following four functions:

Data transmission, addressing, routing, packet segmentation.

Provides a non-connected transport service: IP protocol header, data fields.

TCP protocol

TCP is an important transport layer protocol that allows the data to be reliably exchanged with other nodes on the network.

Udp:

UDP is also a Transport layer protocol, no connection unreliable transport protocol. Throw away not to re-send.