Computer network review-application layer

6.1 Domain Name System DNS

• The main points of the process of unlinking domain name to IP address:
  
• Internet domain name structure
  
• Internet domain name space
  
  

A privilege area under the jurisdiction of domain name servers is called zone .

• Domain name resolution process
  
  
  

6.2 FTP

• How FTP works
  
  

TFTP

World Wide Web WWW

• The difference between hypermedia and hypertext
  

• The World Wide Web works in C/S mode

• Problems to be solved by the World Wide Web:

  • 
  • 
  • 
  • 

• The following introduces the knowledge points in the above solutions one by one

  • URL Uniform Resource Locator
    
    General form:
  • HTTP Hypertext Transfer Protocol
    
    HTTP protocol itself is connectionless , even if it uses the service provided by TCP.
    
    
  • HTML Hypertext Markup Language
    
    • HTML format and tags
      
    • Dynamic and static World Wide Web documents
      Use CGI programs to create dynamic documents.
      
    • The active document
      is run by the browser.

• Proxy server
  
  

• e-mail
  

  • Web-based email
    

• DHCP Dynamic Host Configuration Protocol
  
  

  • DHCP uses client server mode
    
    • DHCP relay agent
      
      
  • Lease period