Computer Network Technology and Application

Chapter 21 Services Provided by the Internet (3)
6.5.3 How the WWW works

(1) The browser determines the URL.

(2) The browser asks DNS for the IP address of the WWW server.

(3) DNS returns IPW as the IP address of the WWW server.

(4) The browser establishes a TCP connection with the service port of IPW.

(5) The browser uses the GET command to request the transmission of a specific page.

(6) WWW server response page.

(7) Release the TCP connection.

(8) The browser displays the requested text information.

(9) The browser fetches and displays all the images of the page.

It can be seen from the above principles that the WWW service needs the support of transmission control connection and DNS service.

6.5.4 Example of using IIS to establish WWW service

Continue with the following after opening IIS.

(1) Open the property setting window of "Default Web Site", right-click "Default Web Site", and select Properties.

(2) Set "Web site". In the "IP address" column, select the IP address of the Web server; "TCP port" is 80.

(3) Set the "main directory".In "Local path", select the directory where the webpage file is located through the "Browse" button.For example, D:\Myweb.

(4) Set "Document".Make sure that "Enable Default Document" is selected, then add the desired default document name and adjust the search order accordingly.Its function is that when only the domain name (or IP address) is entered in the browser, the system will automatically search for the specified file name in the list in the "main directory" according to the "order" (from top to bottom). The first one will call the first one, otherwise it will search for and call the second one, the third one... If there is no file name in this list in the "main directory", it will display an error message that the file cannot be found.

(5) Other items can not be modified, just press "OK", then a dialog box such as "Inherit Overwrite" will appear, select "Select All" and then press "OK".

(6) Additional virtual directories can be added if necessary.For example, "www.uibe.com/news", "news" can be the next-level directory of the "main directory" (let's call it the "actual directory"), or it can be in any other directory.To create a virtual directory under the "Default Web Site", right-click the "Default Web Site" and perform the "New" → "Virtual Directory" operation.Then in "alias"

Enter "news" at "Directory" and select its actual path (such as "E:\NewSweb").

(7) Test: Open a browser on the server or any workstation, enter the IP address of the Web server in the address bar, such as "http://192.168.0.100" and press Enter, if the settings are correct, you can directly call out the IP address of the web server. required page.

Explanation: There are a lot of software that can create Web services. In addition to IIS, there are products from companies such as SUN.

【chapter summary】

This chapter introduces the role of OSI session, representation and application layer; it focuses on the services and related protocols provided by the application layer used on the Internet, including client/server mode, DNS, WWW, FTP, MAIL and other main contents, especially worth mentioning Pay attention to the resolution process of DNS and the working principle of FTP and WWW.

【Difficulties in this chapter】

(1) Client/server mode.

(2) The working principle of WWW.

(3) The process of domain name resolution.

Exercise 6
[-]. Multiple choice questions

1. Regarding e-mail in the Internet, which of the following statements is incorrect ().

A. The main function of the email application is to manage mail
B. Email applications can use SMTP to receive emails and POP3 to send emails

C. E-mail consists of two parts: header and body

D. E-mail can be used to send multimedia information
2. Internet domain name resolution needs to be completed with the help of a group of independent and cooperative domain name servers. The logical structure of these domain name servers is ().

A. Bus type

B. Tree type
C. Ring
D. star
3. The characteristics of HTML language include ()

A. Versatility, simplicity, scalability, and platform independence

B. Simplicity, reliability, scalability, platform independence

C. Versatility, simplicity, authenticity, and platform independence

D. Versatility, simplicity, scalability, security

4. Many FTP servers provide anonymous FTP services.Unless otherwise specified, the anonymous FTP account is ().

A.anonymous B.guest C.niming D.anonymous
5. Currently, the transport protocol used by Web services is ().

A.TCP
B. HTTP
C.UDP
D. SMTP
6. The agreement to solve the virtual terminal problem should be in ().

A. Transport layer or session layer

B. Application layer

C. High-level protocol-presentation layer

D. Low-level protocol - network layer

7. The main function of the gateway is ().

A. Conversion between protocols

B. Exchange data
C. Receive and amplify the signal

D. Check for errors

8. The top-level domain name of China is ().

A.cn
B.com
C.ch
D.net
Two, short answer questions
1. Short answer FTP service content.

2. The role of the short-answer HTTP protocol.

3. Short answer the role of IIS.

4. Briefly answer why the client/server model is adopted on the Internet.

Experiment [-] learning to set up a network server

【Purpose】

(1) Learn to make a simple web page.

(2) Learn how to use IIS to configure the Web server.

【Experimental content】

(1) Establish DNS resolution server.

(2) Install the IIS accessories.

(3) Set up a Web site.

[class time] 2/4
【Experimental Requirements】

(1) Master the installation method of IIS.

(2) Master the configuration method of the Web server.

(3) Master the establishment and configuration methods of the DNS server.

【Experimental conditions】

A computer with Windows Server 2005 operating system, and configure it with IP address: 192.168.0.3.

【Experimental steps】

On the local area network or on the Internet, the computer can only recognize its IP address when communicating on the network, but when you open the browser and enter, for example, "www.uibe.edu.cn" in the address bar, you can see the desired URL. page, which is the domain name resolution introduced in the theoretical part of this chapter.Therefore, if you use a domain name, you need to use a "DNS server" computer. This experiment first establishes DNS resolution services, and then establishes services such as Web.

1. Establish domain name service
(1) Add DNS service
If the DNS service has not been added after installing the Windows Server operating system, follow the steps below to add the service.

① Open "Control Panel" → "Add/Remove Programs" → "Add/Remove Windows Components", select "Network Services" in the component list, click "Details", select "Domain Name Service System (DNS)" from the list , click OK.

②Click "Next", select the path of the Windows Server installation source file through "Browse", and click "OK"

Start to install the DNS service, just follow the wizard to execute.

Tip: Prepare the system installation disk before installing the service, and the version must be consistent with the current system.

(2) Establish a forward lookup zone in DNS

① Click "Start" → "Programs" → "Administrative Tools" → "DNS" to open the "DNS" console window.

②In the "DNS" console window, open the "Operation" menu, select "Create New Zone", and the "New Zone Wizard" will pop up

Dialog box.

③Click "Next", and the "Area Type" dialog box will pop up, select "Standard Main Area".

④ Click "Next", and the "Forward or Reverse Search Area" dialog box will pop up.Select the "Forward Lookup Area" radio button, click "Next" to enter the area name setting.Enter "HAPPY.com" in "Name" and click "Next" to enter the zone file naming step.The default name is "HAPPY.com.dns", this item cannot be changed at will, click "Next", click "Finish".

⑤ Right-click "HAPPY.com" established in the "Forward Search Area", select "New Host" in the pop-up menu, enter "WWW" in the name, and enter the IP address of the corresponding WWW server in the IP address: 192.168.0.3 .[-], click Add Host.

You can repeat steps (1) to (5) above to create other forward search areas, such as "ftp.HAPPY.com", and the IP address of the corresponding FTP server is also 192.168.0.3.

2. Add IIS service
Open the "Control Panel", double-click "Add/Remove Programs", and add "Internet Services (IIS)" in "Add/Remove Windows Components". All the files required by the IIS service include the FTP transfer protocol and the HTTP protocol for providing Web services.

3. Establish WWW server

This experiment uses Internet Service Manager to build a Web site.

(1) Click "Start" → "Programs" → "Administrative Tools" → "Internet Service Manager" to open the "Internet Information Services" management window. The window displays the Internet services that have been installed on the computer and have been automatically started Run, where the Web site is the "default Web site".

(2) Open the property setting window of "Default Web Site", click "Default Web Site", right-click "Properties".

(3) Enter the descriptive text "HAPPY" in the "Web site description" text box.

(4) Set "Web site": "IP address" select "192.168.0.3", "TCP port" is 80.

(5) Set "Main Directory": In "Local Path", select the directory where your webpage files are located through the "Browse" button, for example, D:\Myweb.

(6) Under the "Web Site Access Permissions" item, the "Read" and "Run Script" check boxes are selected by default.Disable the "Write" checkbox to not give modify permissions to the visitor.

(7) Set "Documents", the effect is that when only the domain name (or IP address) is entered in the browser, the system will automatically search for the specified files in the list in "order" (from top to bottom) in the "Main Directory". If the first one can be found, call the first one; otherwise, search for and call the second, third... If there is no file name in this list in the "main directory", it will display the find File not found error message.

(8) Other items do not need to be modified, just “OK” directly.At this time, some dialog boxes such as "Inherit Override" will appear. Generally, select "Select All" and then "OK" to finally complete the property setting of "Default Web Site".

(9) If necessary, add a virtual directory: such as "www.HAPPY.com/news", "news" can be the next-level directory of the "main directory" (called "actual directory") , or in any other directory, the so-called "virtual directory".

(10) To create a virtual directory under "Default Web Site", select "Default Web Site", right-click "New" and select "Virtual Directory", enter "news" in "Alias", and select it in "Directory" Just the actual path (such as "D:\news").

(11) TEST.Open a browser on another computer or this machine, enter "http://www.HAPPY.com" in the address bar and press Enter. If the settings are correct, you should be able to directly access the page you need.

After adding the Internet service, the "Administrative Tools" option will appear in the "Control Panel".Double-click "Administrative Tools" and select "Internet Server Management".

4. Establish FTP server

(1) Right-click "Default FTP Site" and select "Properties" to set the FTP site.

① The IP address of the FTP site, choose 192.168.0.3 for this experiment.

②Port number of FTP service, the default is 21.

(2) Establish an FTP site, set FTP identification instructions, connect settings and enable log records and other functions.

(3) Set up a security account, which is used for account setting.

(4) Set the message, here you can set the message displayed when the user accesses the server.

(5) Set the FTP main directory, and set the main directory path that users visit when they visit this FTP site.

① In IIS Manager, expand the local computer, expand the "FTP Site" folder, right-click the FTP site to change the home directory, and then click "Stop".

② Right-click the FTP site again, and then click "Properties".

③Click the "Main Directory" tab.

④ Under "Content source for this resource", click the location of the main directory.

⑤Click "Apply" and "OK".

⑥Right-click the stopped FTP site, and click "Start".

Optional: Move or copy the contents of the FTP site from the original home directory to the new home directory.

(6) Directory security, set the authorization list of IP access restrictions for users accessing this FTP server.

So far, the FTP server setup has been completed.

5. Inspection

Enter the IP address in the address bar of a browser on a computer, or give your own IP address to a friend, and ask him to access your machine and download what he needs.

【Questions and Thoughts】

(1) How to set up an FTP server in IIS?
(2) What type of site is BBS?

(3) If a server provides 3 different WWW services, how to set them up?
(End of this chapter)