Find Sporting Goods on eBay
Video and Audio], Broadcasting and podcasting Real Time Media On The Net

[description], Story, any other text you want to use.

Understanding DNS

 by: Clare Lawrence

How to understand the Domain Name System

Ever wonder why DNS systems came into existence? Efficiency. Every computer has a distinct IP address, and the Internet needed an elite method for obtaining these addresses and for managing the system as a whole. Enter ICANN.

The Internet Corporation for Assigned Names and Number manages the DNS root of the Internet domain namespace. ICANN's role is to manage the assignment of identifiers, ensuring that all users have unique names.

The DNS system is run by a series of servers called DNS servers. ICANN manages the root DNS domains, under which are the top-level domains.

It also manages:

  • Organizational domains

  • Geographical domains

  • Reverse domains

Beneath the top-level domains are other naming authorities such as Nominet, the UK's naming authority.

How does a DNS Query work?

The process occurs in two parts. Firstly, a name query begins at a client computer and is passed to DNS client service for resolution. When the query cannot be resolved locally, DNS servers are queried.

For example, when a web browser calls the fully qualified domain name www.discountdomainsuk.com, the request is passed on to the DNS client service to resolve the name by using locally cached information. If the query is held in the cache, then the process is complete.

If, however, the query cannot be answered locally, the DNS client service uses a server list (ordered in sequence) to query external DNS servers. When a DNS server receives a query, it first checks to see if it is authoritive for that domain name. If it is authoritive, it resolves the name, and the process is complete.

If the DNS server is unable to resolve the query, it in turns queries other DNS servers, using a process known as recursion. DNS servers make use of root hints to assist in locating DNS servers, which are able to provide the required result. In this way, DNS queries are minimised and the Internet is able to operate quickly and effectively.

A typical query may run as follows:

Client contacts Nameserver A looking for www.discountdomainsuk.com.

Nameserver A checks its cache, but can't answer, so it queries a server authoritive for the Internet root.

The root server responds with a referral to a server authoritive for the .com domains. NameserverA queries the the .com server and gets referred to the server authoritive for www.discountdomainsuk.com.

Nameserver A queries this server and gets the IP address for www.discountdomainsuk.com.

Nameserver A replies to the client with the IP address.

Queries can return answers that are authoritive, positive, negative or referral in nature. In the event of a negative answer, another DNS server is queried.

By Clare Lawrence 13th August 2004

About The Author

Clare Lawrence is CEO of Discount Domains Ltd A leading UK provider of Domain name registration and Web Hosting services. Please feel free to re-publish this article provided this reference box remains together with a hyperlink to http://www.discountdomainsuk.com Clare can also be contacted on clare@discountdomainsuk.com.


web site hosting
cable tv test chips
live interactive webcast
netshow
cable tv decoder
satellite television tv
radio control
streaming video production
telechargement
gadgets
high speed internet access
persian satellite television
npr
dsl service provider
webradio
video server

Main Menu
Real Time Media On The Net
Site Map

Affiliate Ads, Links, news, etc.

News for 19-Aug-20

Source: BBC News - Home
Yemen's displaced

Source: BBC News - Home
US issues Jordan travel warning after deadly attacks

Source: BBC News - Home
500 years later

Source: BBC News - Home
Africa's top shots: 16-22 December 2016

Source: BBC News - Home
Libyan hijacker arrested in Malta

Source: BBC News - Home
Syrian girl with severe burns gets life-changing surgery

Source: BBC News - Home
The longest kiss

Source: BBC News - Home
Libya Malta hijack: Hijackers arrested as drama ends peacefully

Source: BBC News - Home
Wedding gift alpaca has 'surprise' baby

Source: BBC News - Home
Obama's snowman phobia


Links
Links
Links
Google

Talk On The Net | Go Meetings | Medical Newscast | Broadcast On the Net
Copyright © 2005. Name of Site here. Last Updated: Wednesday, 19-Aug-2020 00:01:16 MDT.
Listen On The Net   fantasy-sports-directory   Meetings On The Net