Què és DNS i com funciona?

DNS stands for domain name system. This is a fascinating system that enables the Internet to work. The main job of the DNS is to take the alpha domain name that you enter into your browser and translate it into the numeric IP (internet protocol) address that computers understand.

The site where you register your domain holds the main DNS record for your domain. This record points to where your website is hosted. When we first set up our domains on GKG.net, the DNS record pointed to GKG since the domains were parked on GKG. When we created websites using web hosts outside of GKG, we changed the DNS server record on GKG to point to the DNS server of the hosting website. We have some sites on Hostmonster.com and some on Hostexcellence.com. If you look at our domain registration records on GKG, the DNS server records will either say Primary - NS1.HOSTMONSTER.COM, Secondary - NS2.HOSTMONSTER.COM, or Primary - NS1.HOSTEXCELLENCE.COM, Secondary - NS2.HOSTEXCELLENCE.COM.

The site where you are going to host your site will tell you the names of its name servers so you can change the record on your domain registration site to point to the web host name servers.

DNS servers are specified as primary and secondary. If for some reason, the primary name server does not respond, the browser will automatically query the secondary name server.

When someone enters www.boomer-ezine.com into the browser, it goes onto the Internet and looks for a DNS server to resolve the alpha name to the proper IP address. There are certain companies or organizations that are responsible for certain types of web addresses. Network Solutions, Inc. is responsible for all .COM addresses so the DNS server at Network Solutions (or a similar root server) would be accessed to get the proper IP address. When the URL was matched to the IP address, the returned IP address is 66.116.252.10. Your browser would then use this IP address to load the home page of Boomer eZine.
If you enter http://66.116.252.10 into your browser address window, you will also get Boomer eZine. You can use the IP address of a site to access it directly as well as the domain name.

Just think of the logistics of this system. There are billions of IP addresses used on the Internet. The DNS is basically a large, distributed database used to translate alpha domain names into the numeric IP address that the Internet can use to locate a particular computer on the Internet.

The database is distributed since certain servers are the master servers for certain types of domain names. The United Kingdom is in charge of all .uk domains, Russia is in charge of all .ru domains, and so on. Yet all of these servers are tied together to maintain a naming and lookup system so no domain name is duplicated on the Internet.
I recommend that you read the article about DNS on the How Stuff Works website at http://www.howstuffworks.com/dns.htm. This article does a good job explaining in more detail how this amazing database works.

Just remember that every time you enter a domain name or an email address, the DNS servers are working for you to resolve the alpha name to an IP address and give you the webpage you want. It all is done is milliseconds between your browser and multiple DNS servers and you don't ever realize that it has happened. The webpage you wanted appears and that is all you really care about. ..... Amazing!

Copyright 2006 John Howe, Inc.