Difference between revisions of "DNS"

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(Created page with '''Acronym''. '''D'''omain '''N'''ame '''S'''erver. A server which translates a Domain Name into one or more IP Addresses. == More info == * Also known as '''Name Serve…')
 
 
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A server which translates a [[Domain Name]] into one or more [[IP Address]]es.  
 
A server which translates a [[Domain Name]] into one or more [[IP Address]]es.  
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When using a [[Web Browser]], '''DNS''' takes the part between "http://" and the first slash "/" and converts it into an [[IP Address]], which is a very large number which uniquely identifies a [[Web Server|web server]] on the internet.
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For example for the web address:
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<nowiki>http://www.example.com/</nowiki>
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DNS takes the term '''www.example.com''' and converts it into an IP address: 192.0.32.10
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== DNS Applications ==
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'''DNS''' is used as the primary way of converting names on the internet to addresses. Any application which accesses the internet uses '''DNS''' first to find a server. Because '''DNS''' is the first step used in any internet transaction, it is the target of security breaks. {{!}}
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'''DNS''' is used by the following applications:
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* [[Web Browser]]
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** To resolve the host portion of a [[URL]], and any additional [[URL]] on a page.
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* Email Program
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** To resolve your email server's [[IP Address]], and to determine the [[MX|Mail Exchanger]] for outbound email.
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** Recently, to retrieve a [[DomainKeys]] record to authenticate a sender of an email
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* FTP Program
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** To resolve the host name of a remote FTP server
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* Operating System
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** To resolve the name of your vendor's servers for ''Software Update ...'' (Mac OS X), or ''Windows Update ...'' (Windows)
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* Any application which checks for software updates
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** To resolve the name of the vendor's host server
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== DNS Tools ==
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On Linux, FreeBSD, Mac OS X, or any variant, you can use a command line tool (using iTerm, Terminal, xterm, or some similar shell tool) to perform '''DNS''' on the fly using the ''host'' command:
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> '''host www.example.com'''
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www.example.com has address 192.0.32.10
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On Windows, to perform '''DNS''' requests, go to the '''Start Menu''', then '''Run ...''', and type in '''nslookup''':
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Default Server: acumen
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Address: 192.168.0.1<br />
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> '''www.example.com'''
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Server: acumen
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Address: 192.168.0.1<br />
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Non-authoritative answer:
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Name: www.example.com
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Address: 192.0.32.10
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You can just enter the name you wish to resolve and it will output the response from your local '''DNS''' server.
  
 
== More info ==
 
== More info ==
 
* Also known as '''Name Server''' or one word: '''Nameserver'''
 
* Also known as '''Name Server''' or one word: '''Nameserver'''
 
* See [http://en.wikipedia.org/wiki/Name_server Name Server] on Wikipedia
 
* See [http://en.wikipedia.org/wiki/Name_server Name Server] on Wikipedia
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[[Category:Acronym]]
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[[Category:Glossary]]

Latest revision as of 19:00, 4 December 2009

Acronym. Domain Name Server.

A server which translates a Domain Name into one or more IP Addresses.

When using a Web Browser, DNS takes the part between "http://" and the first slash "/" and converts it into an IP Address, which is a very large number which uniquely identifies a web server on the internet.

For example for the web address:

http://www.example.com/

DNS takes the term www.example.com and converts it into an IP address: 192.0.32.10

DNS Applications

DNS is used as the primary way of converting names on the internet to addresses. Any application which accesses the internet uses DNS first to find a server. Because DNS is the first step used in any internet transaction, it is the target of security breaks. |

DNS is used by the following applications:

  • Web Browser
    • To resolve the host portion of a URL, and any additional URL on a page.
  • Email Program
    • To resolve your email server's IP Address, and to determine the Mail Exchanger for outbound email.
    • Recently, to retrieve a DomainKeys record to authenticate a sender of an email
  • FTP Program
    • To resolve the host name of a remote FTP server
  • Operating System
    • To resolve the name of your vendor's servers for Software Update ... (Mac OS X), or Windows Update ... (Windows)
  • Any application which checks for software updates
    • To resolve the name of the vendor's host server

DNS Tools

On Linux, FreeBSD, Mac OS X, or any variant, you can use a command line tool (using iTerm, Terminal, xterm, or some similar shell tool) to perform DNS on the fly using the host command:

> host www.example.com
www.example.com has address 192.0.32.10

On Windows, to perform DNS requests, go to the Start Menu, then Run ..., and type in nslookup:

Default Server: acumen
Address: 192.168.0.1
> www.example.com Server: acumen Address: 192.168.0.1
Non-authoritative answer: Name: www.example.com Address: 192.0.32.10

You can just enter the name you wish to resolve and it will output the response from your local DNS server.

More info

  • Also known as Name Server or one word: Nameserver
  • See Name Server on Wikipedia