The backbone of the Internet is DNS – the domain name system. The DNS is so important because DNS takes the friendly name of a website like www.netdio.net and translates it from a name we humans can understand, into an IP address that computers understand. As you would expect, it’s easier to remember www.netdio.net rather than it’s IP address of 192.185.226.172.

Here’s how it basically works.

You type in the URL, (uniform resource locator) into a web browser. Your computer then sends a request to a DNS server. The DNS server then translates the URL into an IP address that your computer can use to find the website your searching for.

As a computer user, you may experience some problems related to DNS and you may save yourself time and a few headaches by knowing some basic knowledge.

 

How to find the IP address or a DNS name.

  1. Open the Command Prompt by clicking the Start button. In the search box, type command, and then press enter.

  2. At the command prompt, type nslookup, a space, and the IP address or domain name and then press enter.

What is the DNS cache?

When you type in the domain name of a website into your Internet browser and press enter, your computer sends a query to a DNS server. If the computer gets a reply from the DNS server, then the website you entered will appear, if not, then you get an error. A record of these transactions are stored temporarily on your computer called the DNS cache. The next time you type in the website the computer checks the DNS cache and if the record is there the computer will use it instead of going to a DNS server. This is a faster process because the the record is on your computer and the computer doesn’t have to waste time by checking the DNS server.

How can I see what's in the DNS cache?

Open the Command Prompt by clicking the Start button. In the search box, type command, and then press enter.

At the command prompt, type ipconfig /displaydns and press enter.

How can I purge the DNS cache?

There may be times when you wish to purge the DNS cache and force the computer to check the DNS server instead. A few examples of when you would want to do this is if you’re updating a website and making changes, or if you’re getting errors when trying to browse a website and you know it should be working.

  • Click the Start button.
  • In the search box, type command prompt.
  • In the list of results, right-click Command Prompt, and then click Run as administrator. Administrator permission required If you’re prompted for an administrator password or confirmation, type the password or provide confirmation.
  • At the command prompt, type ipconfig /flushdns and press enter.