Understanding how DNS works in hosting and websites

In the world of the Internet, DNS (Domain Name System) is an essential component for the smooth running of hosting and websites.

It makes web browsing smooth and fast.

Here is a more detailed explanation from our Web Agency:


What is DNS?

DNS is a system for associating an IP (Internet Protocol) address with a domain name. domain name. To simplify the definition, this means that it acts as an address book for computers that communicate with each other via the Internet.

When an Internet user wishes to visit a websitehe types the address URL which then queries the DNS servers to find out which IP address the domain name corresponds to.

How does DNS work?

The different components of DNS

The DNS system is based on a hierarchical and distributed architecture, including several types of servers:

  • Root servers :¬†They contain all the information on top-level domains (TLDs).
  • TLD servers :¬†They provide information on second-level domains (SLDs).
  • Authoritative DNS servers :¬†They contain all the data relating to specific domain names.
  • Recursive DNS servers :¬†They are generally used by Internet clients to query the DNS system and obtain the IP address corresponding to a domain name.

Name resolution: step by step

When a user wants to access a website, they enter its address in the browser. Here are the various steps that take place in the background to convert this domain name into an IP address:

    1. The browser queries the recursive DNS server (generally provided by the Internet service provider) to find out the IP associated with the domain name.
    2. If the recursive server already has the response in cache memory, it responds immediately. Otherwise, it queries the root server to find out which TLD server should be consulted depending on the domain name extension (.com, .fr, .net...).
    3. Once the TLD server has been identified, the recursive server asks it which authoritative server it should contact to obtain information about the SLD in question.
    4. The TLD server then transmits the address of the authoritative server containing the information relating to the requested domain.
    5. Finally, the recursive server asks its question to the authoritative server, which will give it the IP address corresponding to the domain name it is looking for. This IP is then sent back to the user's browser, which will establish the connection with the server hosting the website.

The role of DNS at a hosting provider

When you take out aaccommodationyour service provider can provide you with DNS servers to manage the domain names associated with your websites. Here are some of the main DNS-related services provided by hosting providers:

  • DNS zone management :¬†configuration and updating of DNS records (A, AAAA, CNAME, MX, etc.), enabling you to redirect a domain name to the IP address of your choice or configure the associated e-mail service.

  • Automatic replication of DNS data :¬†regular, automated updating of DNS entries on several servers, to ensure greater resilience to outages and reduced latency.

  • Zone transfer service (AXFR) :¬†synchronisation of DNS data between different authoritative servers, necessary in particular when changing host.

  • Securing DNS data :¬†protection against malicious attacks (DDoS, spoofing, etc.) thanks to mechanisms such as DNS data integrity checking (DNSSEC).

DNS and publishing a website: how does it work?

You've chosen a web host for your website and obtained a domain name: now it's time to publish your site online. Here are the main steps to get you there:

  1. Upload your site files (HTML, CSS) on the hosting server using FTP software.
  2. To ensure that your domain name points to the IP of the hosting server, log in to the management interface for your domains and change the DNS entries (A record) accordingly. It may take some time (from a few minutes to several hours) for the changes to be taken into account by all the DNS servers.
  3. Make sure that your hosting provider has linked your domain name to your hosting account. This is usually done automatically when you subscribe to the hosting package.

In short, DNS is a key element in Internet hosting and browsing.

Thanks to this ingenious, high-performance system, Internet users can access the websites they are looking for quickly and easily, while web hosts provide essential services to guarantee the security and effectiveness of domain names.

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