Some views on TCP/IP (1)

There is less than a year to get ready to find a job, think about the experience of senior, found that the current self or weak explosion. So want to seize the time to enrich themselves, for later in the computer industry to find work lay the foundation.

To the computer company, the knowledge of the network is indispensable, especially the TCP/IP protocol as the focus. Below and you share my views on TCP/IP, I hope to have a good exchange with you.

The TCP/IP protocol is actually a protocol family, only the TCP protocol and IP protocol is used most, so he fateful the name.

Referring to the OSI 7-layer model, the TCP/IP protocol family can be divided into application layer, transport layer, network layer and data link layer. Let's introduce some understanding of the next link layer today.

1. Data Link Layer

For example, the link layer of the work is mainly how to carry out the letter, is to use the car or train, is to go to Beijing this line, or Hangzhou to Tianjin to Beijing; The network layer acts like a signpost, indicating that the letters are to be sent to Beijing, but need not know which one of the places in Beijing This work is done by the transport layer, which completes the end-to-end work by giving the letter to the final recipient (similar to the job of The courier); The application layer is to tell the addressee the contents of the letter, similar to the content of the letter.

The link layer mainly involves the driver of network card and network card. We know that each computer has a physical address (network card address), a total of 48 bits, to indicate the address of the network card, and the driver mainly set a set of rules, that is, the frequency and speed of data transmission between the NIC.

The main running protocols on the link layer are the Ethernet protocol and the token ring. The transmission of information in Ethernet has a standard protocol, that is, how to encapsulate the data to be transmitted, and how the receiver can split to obtain the actual data, refer to the Ethernet message format.

Another important link layer knowledge includes the ARP protocol and the RARP protocol, where ARP maps the IP address to the physical address, rarp the other way around.

In general, the link layer as the basis of the above layers, the data to be sent by the upper layer gradually increased the packet header package to the link layer to transmit, the receiver after the link layer received the message after the removal of the Ethernet packet header and the end of the message to the network layer to resolve.

Some views on TCP/IP (1)