What is DNS?


DNS is an acronym for Domain Name Server, Domain Name Service, or Domain Name System. Consider a user requesting a web page on a browser to show why we need Domain Name Servers.

When you type in a domain name into a browser (such as begincodingnow.com) the browser needs to get the web page associated with that address and sent it back to the browser. To do that it needs to find the computer on the Internet that hosts the web site in question. To find the computer it need to know the IP address of that hosting computer. The browser needs to do a lookup of the IP address based on the domain name. The browser goes to Domain Name Servers to do the job.

Domain Name Servers are the Internet’s equivalent of a phone book. They maintain a directory of domain names and translate them to Internet Protocol (IP) addresses. Why do they do this? IP addresses are part of the Internet Protocol suite and are used to identify particular computers on the Internet. However, a computer can have more than one IP address. So, information from all the domain name servers across the Internet are gathered together and housed at the Central Registry. Host companies and Internet Service Providers interact with the Central Registry on a regular schedule to get updated DNS information.

After you register a new domain name or when you update the DNS servers on your domain name, it usually takes about 12-36 hours for the domain name servers world-wide to be updated and able to access the information. This 36-hour period is referred to as propagation.

If you want to know more information about a web site you can go to whois.net and type in the web address (URL) and you may get names and the address of the company if they have not made that information private. When you register a domain name you have the option of making it private if you pay an extra fee.

StatsInfinity.com is a website that that provides unique internet statistics. The website says about itself: “The most obvious four purposes StatsInfinity is used for are finding great domain names (for registration), investigating a website (for example before you subscribe to a service), for diagnosing one’s own website (DNS etc..), and finally, for finding your internet neighbours (what other websites are hosted with you on the same server).”

Windows Domains

Most Windows Domains have their own DNS servers that maintain the records for all of the computers on their domain. Windows Server has a DNS role that can be installed. Once installed you can take a look at the interface by going to Server Manager, clicking Tools then clicking DNS. The DNS Manager will appear. This manager allows you to manage this DNS server as well as remote DNS servers. To connect to a remote DNS server, simply right click on DNS and select Connect to a DNS Server… You may then specify the computer that is running the DNS server. In a Windows Domain, and on the Windows Server, we can look up a specific computer if we know the computer name. The tool we use is nslookup.

Open a command prompt in the Windows Server by clicking Start and typing cmd and Enter. Type nslookup at the command prompt. If the DNS server is installed and running you will get the name and IP address of the default server. Type exit to quit the ns lookup application.