{"id":120,"date":"2025-02-08T07:19:22","date_gmt":"2025-02-08T07:19:22","guid":{"rendered":"http:\/\/123.249.119.122\/Wordpress\/?p=120"},"modified":"2025-02-12T19:06:05","modified_gmt":"2025-02-12T19:06:05","slug":"the-fundamental-of-website","status":"publish","type":"post","link":"http:\/\/123.249.119.122\/Wordpress\/index.php\/2025\/02\/08\/the-fundamental-of-website\/","title":{"rendered":"The Fundamental of Network"},"content":{"rendered":"\n

1.The Fundamental of Open System Interconnection(OSI)<\/em><\/strong><\/p>\n\n\n\n

Open system interconnection is a module which defined the standard of the interconnection of computer.It’s the framework for designing and discribing the computer network communications.It consists of 7 parts:physical layer,data link layer,network layer,transport layer,session layer,presentation layer,application layer.<\/p>\n\n\n\n

1.1.Physical Layer<\/strong><\/p>\n\n\n\n

Physical layer is the first layer of OSI.It mainly building,maintaining,canceling the physical connection,and realize the transparent transmission of bit stream between adjacent computer nodes.The device of physical layer is optical fiber,network card,and so on.<\/p>\n\n\n\n

1.2.Data Link Layer<\/strong><\/p>\n\n\n\n

Data link layer is the second layer of OSI,building and managing nodes between the link.The device of data link layer is network bridge and switch.It packaging bit information to data frame.<\/p>\n\n\n\n

1.3.Network Layer<\/strong><\/p>\n\n\n\n

Network layer based on the network layer address(IP address),selecting route between different network systems by the routing selection algorithms.The device of network layer is gateway and router.Network layer transmitting data by divided and recombinated data packet. Network layer control the information transmission between data link layer and transport layer.Building,maintaining,terminating the connection of network.<\/p>\n\n\n\n

This is the main problem of realizing network layer function.:<\/p>\n\n\n\n

\u2460Addressing:Any device of every subnet will have it’s sole address for identificating and finding the device in the communication between different subnets.<\/p>\n\n\n\n

\u2461Interchange:Regulating different ways of information interchanging.<\/p>\n\n\n\n

\u2462Routing algorithms:According to the routing algorithm,select the best way of network.<\/p>\n\n\n\n

\u2463Linking service:Control the rate of flow from source node to destination node to detect errors and prevent the congestion.<\/p>\n\n\n\n

1.4.Transport Layer<\/strong><\/p>\n\n\n\n

Transport layer provides transport services between network layer and session layer.This service acquiring data from session layer and divide data when necessary.Then,transport layer tranport data correctly to network layer.The device of transport layer is terminal device like smart phone,personal computer and so on.<\/p>\n\n\n\n

The main function of transport layer is:<\/p>\n\n\n\n

\u2460Transport Link Management:Building,maintaining and dismantling the link.<\/p>\n\n\n\n

\u2461Processing transportation error:Provides reliable ‘facing link’ and not reliable ‘facing no link’ data transport service,error control and rate of flow control.<\/p>\n\n\n\n

\u2462Monitoring the quality of service.<\/p>\n\n\n\n

The main protocol in transport layer is TCP in TCP\/IP,SPX in Novell network,and so on.<\/p>\n\n\n\n

1.5.Session Layer<\/strong><\/p>\n\n\n\n

Session layer is the interface between application and network.It organizing and coordinating the communication between two sessions,and managing the data change.<\/p>\n\n\n\n

The main function of session layer is:<\/p>\n\n\n\n

\u2460Session management:User can build,maintain,terminate the session between two entities,and support the data change between them.<\/p>\n\n\n\n

\u2461Session flow control:Session flow control and cross conversation.<\/p>\n\n\n\n

\u2462Addressing:Build session connection by remote address.<\/p>\n\n\n\n

\u2463Error control: Receive the data from transport layer and correct errors.<\/p>\n\n\n\n

1.6.Presentation Layer<\/strong><\/p>\n\n\n\n

Presentation layer explains the command and data from application layer,define relative grammar,and transport to session layer.<\/p>\n\n\n\n

The main function of presentation layer is:<\/p>\n\n\n\n

\u2460Data format processing:Process the format of data changing,fix the difference between applications.<\/p>\n\n\n\n

\u2461Data coding:Process the changing between number and character set.<\/p>\n\n\n\n

\u2462Compress and extract:Compress and extract data to reduce the data transportation.<\/p>\n\n\n\n

\u2463Data encryption and decryption:Enhance the network safety.<\/p>\n\n\n\n

1.7.Application Layer<\/strong><\/p>\n\n\n\n

The main function of application layer is:<\/p>\n\n\n\n

\u2460User interface:User can interconnect to the network and application by user interface.<\/p>\n\n\n\n

\u2461Services:The application can povides service to finish and respond user’s requests.<\/p>\n\n\n\n

2.The Essential Conception of Network<\/em><\/strong><\/p>\n\n\n\n

Device:The network card in the host.<\/p>\n\n\n\n

Broadcast Address:Addresses of all hosts that reach this network segment.<\/p>\n\n\n\n

Interface:The interface between devices or human-machine.<\/p>\n\n\n\n

Subnet Mask:The mask that divides an IP address into a net address and a host address.<\/p>\n\n\n\n

Route:The next address that IP package accessing cross-network segment.<\/p>\n\n\n\n

Link:The connection between devices and network.<\/p>\n\n\n\n

3.The Configuration File of Network <\/strong><\/em><\/p>\n\n\n\n

In Linux operating system,the configuration file of network located in the directory ‘\/etc\/sysconfig\/network-scripts<\/strong>‘.You can read this blog to understand the configuration file:The parameter of the network configuration file in Linux operating system.<\/a><\/p>\n\n\n\n

You can modify the network configuration file by vim editor.You can backup file before it.After the modification,you should input ‘systemctl reload NetworkManager<\/strong>‘ to reload the progress.<\/p>\n\n\n\n

NetworkManager is the daemon progress that dynamically control and configurate the network,maintain the network and link working.We can control NetworkManager by nmcli command.You can input ‘nmcli –help<\/strong>‘ to search commands of nmcli.And then,you can configurating static routes<\/p>\n\n\n\n

4.Route<\/em><\/strong><\/p>\n\n\n\n

You can click this website and read the fundamental of network-routing.<\/p>\n\n\n\n

Gateways and Routes<\/a><\/p>\n\n\n\n

Then,you can input ‘route -n<\/strong>‘ command to watch the route table.And then,you can configuring routes.You can add,delete,modify routes by commands.<\/p>\n\n\n\n

5.Hostname<\/em><\/strong><\/p>\n\n\n\n

You can see your hostname in the file ‘\/etc\/host’,and modify your hostname by hostname command.The file ‘\/etc\/hosts’ shows the IP address and corresponding hostname\/domain name.You can see the DNS by ‘nslookup’ command.<\/p>\n","protected":false},"excerpt":{"rendered":"

1.The Fundamental of Open System Interconnection(OSI) Open system interconnection is a module which defined the standard of the interconnection of computer.It’s the framework for designing and discribing the computer network communications.It consists of 7 parts:physical layer,data link layer,network layer,transport layer,session layer,presentation layer,application layer. 1.1.Physical Layer Physical layer is the first layer of OSI.It mainly building,maintaining,canceling […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-120","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"_links":{"self":[{"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/posts\/120","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/comments?post=120"}],"version-history":[{"count":20,"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/posts\/120\/revisions"}],"predecessor-version":[{"id":144,"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/posts\/120\/revisions\/144"}],"wp:attachment":[{"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/media?parent=120"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/categories?post=120"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/123.249.119.122\/Wordpress\/index.php\/wp-json\/wp\/v2\/tags?post=120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}