Difference between revisions of "DNS"
(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. | ||
+ | |||
+ | 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. | ||
+ | |||
+ | For example for the web address: | ||
+ | |||
+ | <nowiki>http://www.example.com/</nowiki> | ||
+ | |||
+ | 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 [[MX|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<br /> | ||
+ | > '''www.example.com''' | ||
+ | Server: acumen | ||
+ | Address: 192.168.0.1<br /> | ||
+ | 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 == | == 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 | ||
+ | |||
+ | [[Category:Acronym]] | ||
+ | [[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
- 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