Knowing DNS

I started thinking about this last night. I know the significance of DNS within my field and I thought I would blog about it today. DNS is such a power tool, the average user uses it all the time and probably doesn’t know it.

DNS plays a huge role in connection everyone to everyone. It starts with your Local Network Connection, for any network connection to work you have to have at least these 3 different settings configured. 1) An IP Address, this is your unique identifier assigned to a media access control (MAC) address which is the hardware that is your device. 2) A Gateway, this needs to be defined so that when you request data it knows where to send it out and expect to receive. 3) DNS Servers, after you have your IP address assigned and Gateway you will need your DNS servers to do resolution requests for you such as….

Let’s say you get your network card setup and want to go to “” well your computer doesn’t automatically know where “” is at. So it sends a request to a DNS server which holds that information. So you are at your computer you type the address in “” the first query that gets asked is where is “.com.” at? The .com is part of what’s called a TLD which stands for Top Level Domain. These are typically government run servers by ICANN. At this level these domain names can not be purchased. Then your query request then looks for the record “google” under the TLD “.com.”. When it finds that record it asks for “www” under “”? Then for each of these requests you have a Public IP address, these are assigned by your Internet service provider (ISP). So the final query that gets sent to your computer returns the value IP address with ( resulting in “”. Your computer then receives all of the information that is provided on the default port 80 at that IP address with that given host header value.

It is vital as a Network Administrator to know that your network is configured correctly. This also is very important to know because when you need to troubleshoot something you will need to know how to solve the problem. If you If you are just learning about the Information Technology field or have an interest, it is very important that you know how DNS works and if there is an underlying issues within your zone records. So that when clients request access to certain sites you know where they are being sent to.

One great thing about DNS that you can utilize is custom domain configuration you can make a domain name “” and tell your DNS server to point to this web server. When you control the DNS you can configure your local DNS to allow “blog” to be a TLD then under that record configure bladityda to point to the specific web server hosting the host header value. These are great for and commonly used in organizations that have internal portals, or intranets.

If you learn DNS like that back of your hand it will make things easier for you and how you can manage your network. I would recommend that you utilize DNS to it’s full potential.

– Harry Caskey

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