What,DNS,amp,#63, computer What is DNS?
----------------------------------------------------------Permission is granted for the below article to forward,reprint, distribute, use for ezine, newsletter, website,offer as free bonus or part of a product for sale as longas no changes a Gone are those times when the companies and the organisations didn't need a hi-tech system to handle them. Owing to the considerable increase in the business sector and thus, an enormous increase in the complexity of the organisational struc
----------------------------------------------------------Permission is granted for the below article to forward,reprint, distribute, use for ezine, newsletter, website,offer as free bonus or part of a product for sale as longas no changes are made and the byline, copyright, and theresource box below is included. ----------------------------------------------------------What is DNS?By Stephen BucaroHave you ever wondered what happens when you enter, orclick on, a web address in your browser? How does yourcomputer connect to the Web site you requested? Part ofwhat makes that happen is the Internet's Domain NameService (DNS).Similar to how every telephone has a unique number, everyWeb site, or "domain" on the Internet has a uniqueInternet Protocol (IP) address. IP addresses are 32 bitnumbers represented by four bytes separated by dots. Eachbyte can represent a number from 0 to 255, therefore thehighest IP address 255.255.255.255.People have difficulty remembering 12 digit numbers, soweb sites are are identified by names like www.sitename.com instead of their IP address. DNS is adatabase of domain names and their corresponding IPaddresses.In the beginning, every computer on the Internet had alist of all the domain names and their corresponding IPaddresses. But that quickly became unwieldy. Now thedomain name database and domain name to IP addresstranslation is performed by computers assigned as DNSservers.Each DNS server has data only about the domains it isserving. When a computer makes a request to its DNS, itis possible that the DNS server doesn't have the datarequired to answer the request. Special "root name"servers hold a list of DNS servers for top-level domains,like .com, .org, .edu etc. For example, the top-level DNSfor .com lists the DNS servers for domain names ending in".com".If a DNS server doesn't have the data to answer a request,it makes a request to a root-name server. The root-nameserver will return the address of a DNS server where thedata can be found.Each domain name on the Internet is required to be listedon a minimum of two DNS servers. This is so if one of theDNS servers goes down, requests for the domains addresscan still be answered.DNS also performs IP address to domain name translation.This makes it possible for servers to log accesses and foradministrators to perform certain administrative andsecurity tasks.Information communicated over the Internet is broken into"packets" by Transmission Control Protocol (TCP). TCPattaches the IP address of the requested domain to eachpacket so that they can be routed to the domain. TCP alsoattaches the IP address of the requesting computer to thepackets so that responses can be routed back.When you enter, or click on, a web address in your browser,the Internet's Domain Name Service (DNS) translates the webaddress to the web sites IP address. This is only part ofthe story of how your computer connects to the Web site yourequested. In a future article you'll learn about theamazing process performed by routers.----------------------------------------------------------Resource Box:Copyright(C)2002 Bucaro TecHelp. To learn how to maintainyour computer and use it more effectively to design a Website and make money on the Web visithttp://bucarotechelp.comTo subscribe to Bucaro TecHelp Newsletter Send a blankemail to bucarotechelp-subscribe@topica.com---------------------------------------------------------- Article Tags: Domain Names, Domain Name
What,DNS,amp,#63,