Dec 27 2010

DNS - The Air That We Breathe

Posted by Mike Brunt at 6:46 AM Web Servers | .NET | DataBase | Caching | ColdFusion | JRun-J2EE



How often do we think about air, the air that we breathe?  Hardly at all, unless of course it becomes scarce or non-existent.  It is the same with Domain Name Services (DNS), hardly thought of at all, yet vital to the operation of the Internet and World Wide Web.  In fact many times when it seems we have overall Internet connectivity issues, it can often be DNS.  A tell-tale clue is if services not dependent on DNS are still working; Skype for instance.

DNS serves to translate domain names into IP Addresses much in the same way that phone books will allow us to find phone numbers from names.  The difference is that no two domain names can be exactly the same.  

In the early days of the Internet, domain names were maintained in local files on each computer system, “host files” as they were called.  As more and more domains were added and more and more servers were added, this system became unwieldy and unmanageable.  So the DNS system we use constantly, began to emerge, in essence a number of distributed databases;  these are called authoritative name servers.  DNS was created in 1983 and in 1984 a Unix based implementation called The Berkeley Internet Name Domain system or “BIND” was created.  In the early 1990’s this was also made available on Windows NT.

In order to ensure that DNS is always available there are multiple servers located all around the Internet and the world, in an interlinked network.  As individual users “clients” we are pointed to the nearest local DNS server and records for every domain and server serving these domains are available to us from there.  As there are very many records to query, a system of caching is used which has a “time to live” value.  The can sometimes cause DNS changes to take time to propagate around the world, hence changes are not initially available everywhere, simultaneously.

Here is a very detailed explanation of the DNS system.

Recently there have been concerns about censorship or control being enforced by Western governments by their seizing domains.  Here is an article relating to that.







solo hd

solo hd wrote on 05/03/11 12:17 AM

This <a href="">solo hd</a> of headset timbre and its appearance style are very alike -- again, very thin. <a href="">beats solo hd</a> voice very open seem a bit too thin, <a href="">Fabulous Monster Limited Edition GOLD</a> low frequency partial hard, descend not beautiful but speed feeling good. <a href=" ">discount solo hd</a> hf performance is good, accurate and not mellow, intermediate frequency performance is regular. Overall <a href="">Classic Monster Powered Isolatio black</a> voice more features, more suitable for listening to electronic music or part of the pop.
crampon nike

crampon nike wrote on 10/28/13 5:24 AM

Thanks for your time.good site.
cheap watches uk

cheap watches uk wrote on 04/22/14 8:53 AM

Some of these are operating locally, while there are some that are affairs their articles onlin.

mercurial wrote on 05/20/14 9:46 AM

The main three varieties of base ball shoes manufacturer as well as vendors would be the Nike and The puma corporation.A number of the less popular producers that will participate in the production of basketball footwear include Lottery.Exactly why the 1st little league footwear were known simply by all of the individuals.
Behance Albert Wesker

Behance Albert Wesker wrote on 05/22/14 2:30 AM

Thanks. Look forward to your writing in my nearest future.
miu miu handbags

miu miu handbags wrote on 08/26/14 12:00 AM

Social media promoting requires the optimum utilization of promoting probable with the functions (compensated advertising facility, contests, company pages in the scenario of Google+, and far more) in social media internet sites. wrote on 10/15/14 4:35 AM

once the flick went to VHS and DVD, you watch it in the confinds of your home, a dinky TV screen and a not so dark and creepy room and all that effectivness is completely and utterly lost and has ZERO "creep" EFFECT.
best essays

best essays wrote on 10/30/14 12:19 PM

Everyone know very well that air is the symbol of life without air no one can live in this earth. I found this post helpful and informative for me. I like your thinking level.

click wrote on 12/26/14 10:35 PM

I am happy to find this post very useful for me, as it contains lot of information. fdbbfbdf wrote on 02/09/15 3:08 AM

The reason for a footballing game is usually to advance this ball in addition to score points into your other competitors end region. The football is usually advanced by means of throwing it completely to another player which is known as a passing engage in or hauling it which is known as a running engage in.
مواقيت الصلاة القاهرة

مواقيت الصلاة القاهرة wrote on 07/19/16 11:32 PM

Thank you for sharing all these informations with us. i find your blog verry informative when it comes about it world and mobile world. keep it up!
مواعيد الصلاة

مواعيد الصلاة wrote on 07/19/16 11:40 PM

bzxdfvbd vdtufjyfjdddf