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What a DNS Does For You

What a DNS Does For You

Posted by Brewcity on February,22 2017

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Everyone online uses a DNS, but many people don't know that the acronym stands for Domain Name Server, or why it's necessary. It is simple, once you understand it.

The Internet Doesn't Use Names, It Uses Addresses

The internet operates on addresses that have a numerical format, not human-recognizable addresses such as google.com. Google has many different servers worldwide, of course, and they all have to have unique addresses, but they will all look something like this: 74.125.224.72 The Internet Protocol Version 4 (IPv4) address will be 4 numbers, none higher than 255, separated by periods. IPv6 numbers are longer, but the idea remains the same; each device on the network has a unique address expressed as a number.

The Domain Name System exists to translate between those numbers and the alphabetic domain name. When you ask your browser to open a page to google.com, the name server supplies the numberic address suited to your location. DNS servers are typically provided by your ISP (Internet Service Provider), though Google offers the same service to anyone on the internet, at the addresses 8.8.8.8 (primary) and 8.8.4.4 (secondary). When you first set your computer to access the internet, you'll tell it which addresses to use for Domain Name System service. These addresses are usually provided by your ISP, which is the first link between you and whatever web page you are using.

Every Domain Name Service Keeps Track Of Changes

New domain names are being registered constantly, so Domain Name System servers talk to one another frequently, sharing information on recent changes. This is fairly quick, but not instantaneous, so a web page at a brand-new domain may take as long as a day to be available from all servers. This process is referred to as propagation, and how quickly it happens depends on the number of systems between the originating server and the server you are asking to look up the new name.

This is the advantage of using a central DNS server, such as Google's. The disadvantage is that the more requests a server receives, the slower the response time will be. The internet was designed for redundancy, to continue to function even if one DNS crashes or goes down from mechanical failure. This is why almost every DNS has a primary and a secondary address; if the primary server goes off-line, the secondary server is there to provide name service until the primary can be brought back on-line.

Domain Name System Error Signs

When your browser reports that it cannot find the server at an address that you're certain is valid, this is a clear indication that the DNS server your system is using is not working properly. Additional resources can be found at www.bluecatnetworks.com