webagain

Web again

First Two Conception

URl vs DNS

URL is locater includeing domian+protocal eg https/ http + yuanxw.top

sometimes you can successfully get your resource typing only domain, which is due to browser help clarify the spec protocol

DNS is a serve, looking at this name. you could guess it should be a series of system to offer a network. Obviously, it is and serves as a convert to domain to spec IP so that you can get your resource you applied for.
IP address

Conventionally, thousands of bloggers usually take the adders as a metaphor of IP. It is straight-forward but the thing is, most people have no idea the spec meaning of address unless your city architecture is modern western style like Chicago.

so I just pop two questions here
1. who give your address or why
2. In real scenario, people know your could find you, how about the virtual life?

Go further

DNS

as the basic description does, DNS work as a converter.

I’d like to go further introducing the application situation.
- TOP-LEVEL Domain
  
  as we all know domain include the Hierarchy architecture like eg
  
  developer.mozila.org
  
  Typically it is divided into three parts or above, while the level definitively ranks from Right to left.
  
  and DNS resolve the name to IP in the same way.
  
  basic sequence is as below:
  
  as the figure shows, DNS server finish resolution rankly as above.
  
  Root Server get .com -> TLD resolve .com -> example get resolved by lower level server
  
  Management
  - Xname alias
    
    In DNS management, to get loader-balance we have to implement some resource to other server like below.
    
    so that people could find some like CNAME when you config a real server like MX name/Aname/cNAME
    
    this subdomain point to the real resource just in replace of the master domain due to loading pressing
    
    this make the searching for resource more fluently.
    
    Note that different name may be records as MX ANAME or else. this is just a simple demo
  Software
  - as we have discussed, System server must include the software layer work.
  - Web server vs Application Server vs Database
    
    Web server as html provider
    
    Application server server as backend which is also called dynamic content
    
    database is interacted with application server
  Firewall
  
  For this part, we only filters through some content as I have popped two questions.
  
  Image what do your ISP provider for you? Not only the wires and your bandwidth. also the firewall in order to your limit internet source.
  
  spec link This link may introduce the concept of intranet and cyber attack
  
  Load Balance
  
  a trade-off of a network
  
  TBD
  
  SSL in HTTP
  
  Datebase

ref:

https://medium.com/basic-command-ls-linux/how-dns-works-b49c7395c91e