A fully qualified domain name (or FQDN) is an unambiguous domain name that specifies the node's position in the DNS tree hierarchy absolutely. To distinguish an FQDN from a regular domain name, a trailing period is added. ex: somehost.example.com. An FQDN differs from a regular domain name by its absoluteness; a suffix will not be added.
For example, given a device with a hostname of "myhost" and a domain name of "example.com", the fully qualified domain name is "myhost.example.com.". It therefore uniquely defines the device — whilst there might be many hosts in the world called "myhost", there can only be one "myhost.example.com.".
Notice that there is a dot at the very end of the domain name, i.e. it ends ".com." and not ".com" — this indicates that the name is an FQDN. For example "myhost.bar.com" could be ambiguous, because it could be the prefix of a longer domain name such as "myhost.bar.com.au", whereas "myhost.bar.com." is a fully qualified domain name. Technically, the dot comes before the empty label indicating the root of the Domain Name System hierarchy, and so an FQDN is sometimes called a rooted domain name. In practice, the dot is almost always omitted in everyday applications, making such domain references technically ambiguous.
The maximum permitted length of an FQDN is 255 bytes, with an additional restriction to 63 bytes for each label within the domain name. The syntax of domain names is discussed in various RFCs — RFC 1035, RFC 1123 and RFC 2181. Any binary string can be used as the label of any resource record; a common misconception is that names are limited to a subset of ASCII characters.
Internationalized domain names expand the character repertoire of domain names to include non-ASCII characters, by encoding Unicode characters into byte strings within the normal FQDN character set. As a result, the character length limits of internationalized domain names are content-dependent.
Monday, November 26, 2007
DOMAIN TASTING
Domain tasting, also known as domain kiting, is a practice of registrants using the five-day "grace period" at the beginning of a domain registration for ICANN-regulated generic top-level domains to test the marketability of a domain name. During this period, when a registration must be fully refunded by the domain registry, a cost-benefit analysis is conducted by the registrant on the viability of deriving income from advertisements being placed on the domain's web site.
Domains that are deemed "successes" and retained in registrant's portfolio often represent domains that were previously used and have since expired, misspellings of other popular sites, or generic terms that may receive type-in traffic. These domains are usually still active in search engines and other hyperlinks and therefore derive enough traffic such that advertising revenue exceed the cost of the registration. The registrant may also derive revenue from eventual sale of the domain, at a premium, to a third party.
ControversyThe practice is controversial as practitioners typically register many hundreds of thousands of domain names under this practice, with these temporary registrations far exceeding the number of domain names actually licensed.
In April 2006, out of 35 million registrations, only a little more than 2 million were permanent or actually purchased. By February 2007, the CEO of GoDaddy reported that of 55.1 million domain names registered, 51.5 million were canceled and refunded just before the 5 day grace period expired and only 3.6 million domain names were actually kept.
Some claim domain name registries such as VeriSign and the Public Interest Registry have turned a blind eye to the practice as it has dramatically increased the number of registrations secured and renewed. However, this claim is inconsistent with proposals by registries to introduce measures that would reduce or eliminate the practice.
Domains that are deemed "successes" and retained in registrant's portfolio often represent domains that were previously used and have since expired, misspellings of other popular sites, or generic terms that may receive type-in traffic. These domains are usually still active in search engines and other hyperlinks and therefore derive enough traffic such that advertising revenue exceed the cost of the registration. The registrant may also derive revenue from eventual sale of the domain, at a premium, to a third party.
ControversyThe practice is controversial as practitioners typically register many hundreds of thousands of domain names under this practice, with these temporary registrations far exceeding the number of domain names actually licensed.
In April 2006, out of 35 million registrations, only a little more than 2 million were permanent or actually purchased. By February 2007, the CEO of GoDaddy reported that of 55.1 million domain names registered, 51.5 million were canceled and refunded just before the 5 day grace period expired and only 3.6 million domain names were actually kept.
Some claim domain name registries such as VeriSign and the Public Interest Registry have turned a blind eye to the practice as it has dramatically increased the number of registrations secured and renewed. However, this claim is inconsistent with proposals by registries to introduce measures that would reduce or eliminate the practice.
Monday, November 19, 2007
Uses and abuses
As domain names became attractive to marketers, rather than just the technical audience for which they were originally intended, they began to be used in manners that in many cases did not fit in their intended structure. As originally planned, the structure of domain names followed a strict hierarchy in which the top level domain indicated the type of organization (commercial, governmental, etc.), and addresses would be nested down to third, fourth, or further levels to express complex structures, where, for instance, branches, departments, and subsidiaries of a parent organization would have addresses which were subdomains of the parent domain. Also, hostnames were intended to correspond to actual physical machines on the network, generally with only one name per machine.
However, once the World Wide Web became popular, site operators frequently wished to have memorable addresses, regardless of whether they fit properly in the structure; thus, since the .com domain was the most popular and memorable, even noncommercial sites would often get addresses under it, and sites of all sorts wished to have second-level domain registrations even if they were parts of a larger entity where a logical subdomain would have made sense (e.g., abcnews.com instead of news.abc.com). A Web site found at http://www.example.org/ will often be advertised without the "http://", and in most cases can be reached by just entering "example.org" into a Web browser. In the case of a .com, the Web site can sometimes be reached by just entering "example" (depending on browser versions and configuration settings, which vary in how they interpret incomplete addresses).
The popularity of domain names also led to uses which were regarded as abusive by established companies with trademark rights; this was known as cybersquatting, in which somebody took a name that resembled a trademark in order to profit from traffic to that address. To combat this, various laws and policies were enacted to allow abusive registrations to be forcibly transferred, but these were sometimes themselves abused by overzealous companies committing reverse domain hijacking against domain users who had legitimate grounds to hold their names, such as their being generic words as well as trademarks in a particular context, or their use in the context of fan or protest sites with free speech rights of their own.
Laws that specifically address domain name conflicts include the Anticybersquatting Consumer Protection Act in the United States and the Trademarks Act, 1999, in India. Alternatively, domain registrants are bound by contract under the UDRP to comply with mandatory arbitration proceedings should someone challenge their ownership of the domain name.
However, once the World Wide Web became popular, site operators frequently wished to have memorable addresses, regardless of whether they fit properly in the structure; thus, since the .com domain was the most popular and memorable, even noncommercial sites would often get addresses under it, and sites of all sorts wished to have second-level domain registrations even if they were parts of a larger entity where a logical subdomain would have made sense (e.g., abcnews.com instead of news.abc.com). A Web site found at http://www.example.org/ will often be advertised without the "http://", and in most cases can be reached by just entering "example.org" into a Web browser. In the case of a .com, the Web site can sometimes be reached by just entering "example" (depending on browser versions and configuration settings, which vary in how they interpret incomplete addresses).
The popularity of domain names also led to uses which were regarded as abusive by established companies with trademark rights; this was known as cybersquatting, in which somebody took a name that resembled a trademark in order to profit from traffic to that address. To combat this, various laws and policies were enacted to allow abusive registrations to be forcibly transferred, but these were sometimes themselves abused by overzealous companies committing reverse domain hijacking against domain users who had legitimate grounds to hold their names, such as their being generic words as well as trademarks in a particular context, or their use in the context of fan or protest sites with free speech rights of their own.
Laws that specifically address domain name conflicts include the Anticybersquatting Consumer Protection Act in the United States and the Trademarks Act, 1999, in India. Alternatively, domain registrants are bound by contract under the UDRP to comply with mandatory arbitration proceedings should someone challenge their ownership of the domain name.
Top-level domains
Every domain name ends in a top-level domain (TLD) name, which is always either one of a small list of generic names (three or more characters), or a two-character territory code based on ISO-3166 (there are few exceptions and new codes are integrated case by case). Top-level domains are sometimes also called first-level domains.The generic top-level domain (gTLD) extensions are:In addition to the top-level domains, there are second-level domain (SLD) names. These are the names directly to the left of .com, .net, and the other top-level domains. As an example, in the domain en.wikipedia.org, "wikipedia" is the second-level domain.On the next level are third-level domains. These domains are immediately to the left of a second-level domain. In the en.wikipedia.org example, "en" is a third-level domain. There can be fourth and fifth level domains and so on, with virtually no limitation. An example of a working domain with five levels is www.sos.state.oh.us. Each level is separated by a dot or period symbol between them.Domains of third or higher level are also known as subdomains, though this term technically applies to a domain of any level, since even a top-level domain is a "subdomain" of the "root" domain (a "zeroth-level" domain that is designated by a dot alone).Traditionally, the second level domain has been chosen based on the name of a company (i.e. microsoft.com). The third level was commonly used to designate a particular host server. Therefore, ftp.wikipedia.org might be an FTP server, www.wikipedia.org would be a World Wide Web Server, and mail.wikipedia.org could be an email server. Modern technology now allows multiple servers to serve a single subdomain, or multiple protocols or domains to be served by a single computer. Therefore, subdomains may or may not have any real purpose.
DOMAIN NAME
The term domain name has multiple related meanings:
A name that identifies a computer or computers on the internet. These names appear as a component of a Web site's URL, e.g. wikipedia.org. This type of domain name is also called a hostname. The product that domain name registrars provide to their customers. These names are often called registered domain names. Names used for other purposes in the Domain Name System (DNS), for example the special name which follows the @ sign in an email address, or the Top-level domain names like .com, or the names used by the Session Initiation Protocol (VoIP), or DomainKeys. They are sometimes colloquially (and incorrectly) referred to by marketers as "web addresses". This article will primarily discuss registered domain names. See the Domain Name System article for technical discussions about general domain names and the hostname article for further information about the most common type of domain name.
OverviewThe most common types of domain names are hostnames that provide more memorable names to stand in for numeric IP addresses. They allow for any service to move to a different location in the topology of the Internet (or an intranet), which would then have a different IP address.
By allowing the use of unique alphabetical addresses instead of numeric ones, domain names allow Internet users to more easily find and communicate with web sites and other server-based services. The flexibility of the domain name system allows multiple IP addresses to be assigned to a single domain name, or multiple domain names to be assigned to a single IP address. This means that one server may have multiple roles (such as hosting multiple independent Web sites), or that one role can be spread among many servers. One IP address can also be assigned to several servers, as used in anycast and hijacked IP space.
Hostnames are restricted to the ASCII letters "a" through "z" (case-insensitive), the digits "0" through "9", and the hyphen, with some other restrictions. Registrars restrict the domains to valid hostnames, since, otherwise, they would be useless. The Internationalized domain name (IDN) system has been developed to bypass the restrictions on character allowances in hostnames, making it easier for users of non-English alphabets to use the Internet. The underscore character is frequently used to ensure that a domain name is not recognized as a hostname, for example with the use of SRV records, although some older systems, such as NetBIOS did allow it. Due to confusion and other reasons, domain names with underscores in them are sometimes used where hostnames are required.
A name that identifies a computer or computers on the internet. These names appear as a component of a Web site's URL, e.g. wikipedia.org. This type of domain name is also called a hostname. The product that domain name registrars provide to their customers. These names are often called registered domain names. Names used for other purposes in the Domain Name System (DNS), for example the special name which follows the @ sign in an email address, or the Top-level domain names like .com, or the names used by the Session Initiation Protocol (VoIP), or DomainKeys. They are sometimes colloquially (and incorrectly) referred to by marketers as "web addresses". This article will primarily discuss registered domain names. See the Domain Name System article for technical discussions about general domain names and the hostname article for further information about the most common type of domain name.
OverviewThe most common types of domain names are hostnames that provide more memorable names to stand in for numeric IP addresses. They allow for any service to move to a different location in the topology of the Internet (or an intranet), which would then have a different IP address.
By allowing the use of unique alphabetical addresses instead of numeric ones, domain names allow Internet users to more easily find and communicate with web sites and other server-based services. The flexibility of the domain name system allows multiple IP addresses to be assigned to a single domain name, or multiple domain names to be assigned to a single IP address. This means that one server may have multiple roles (such as hosting multiple independent Web sites), or that one role can be spread among many servers. One IP address can also be assigned to several servers, as used in anycast and hijacked IP space.
Hostnames are restricted to the ASCII letters "a" through "z" (case-insensitive), the digits "0" through "9", and the hyphen, with some other restrictions. Registrars restrict the domains to valid hostnames, since, otherwise, they would be useless. The Internationalized domain name (IDN) system has been developed to bypass the restrictions on character allowances in hostnames, making it easier for users of non-English alphabets to use the Internet. The underscore character is frequently used to ensure that a domain name is not recognized as a hostname, for example with the use of SRV records, although some older systems, such as NetBIOS did allow it. Due to confusion and other reasons, domain names with underscores in them are sometimes used where hostnames are required.
Sunday, October 28, 2007
OBTAINING HOSTING
Web hosting is often provided as part of a general Internet access plan; there are many free and paid providers offering these services.
A customer needs to evaluate the requirements of the application to choose what kind of hosting to use. Such considerations include database server software, scripting software, and operating system. Most hosting providers provide Linux-based web hosting which offers a wide range of different software. A typical configuration for a Linux server is the LAMP platform: Linux, Apache, MySQL, and PHP/Perl/Python. The webhosting client may want to have other services, such as email for their business domain, databases or multi-media services for streaming media. A customer may also choose Windows for its hosting platform. The customer still can choose from PHP, Perl, and Python but may also use ASP .Net or Classic ASP.
Web hosting packages often include a Web Content Management System, so the end-user doesn't have to worry about the more technical aspects.
One may also search the Internet to find active webhosting message boards that may provide feedback on what type of webhosting company may suit his/her needs.
A customer needs to evaluate the requirements of the application to choose what kind of hosting to use. Such considerations include database server software, scripting software, and operating system. Most hosting providers provide Linux-based web hosting which offers a wide range of different software. A typical configuration for a Linux server is the LAMP platform: Linux, Apache, MySQL, and PHP/Perl/Python. The webhosting client may want to have other services, such as email for their business domain, databases or multi-media services for streaming media. A customer may also choose Windows for its hosting platform. The customer still can choose from PHP, Perl, and Python but may also use ASP .Net or Classic ASP.
Web hosting packages often include a Web Content Management System, so the end-user doesn't have to worry about the more technical aspects.
One may also search the Internet to find active webhosting message boards that may provide feedback on what type of webhosting company may suit his/her needs.
TYPE OF HOSTING
Types of hosting A typical server "cage," commonly seen in colocation centres.Internet hosting services can run Web servers; see Internet hosting services.
Hosting services limited to the Web:
Free web hosting service: is free, (sometimes) advertisement-supported web hosting, and is often limited when compared to paid hosting. Shared web hosting service: one's Web site is placed on the same server as many other sites, ranging from a few to hundreds or thousands. Typically, all domains may share a common pool of server resources, such as RAM and the CPU. A shared website may be hosted with a reseller. Reseller web hosting: allows clients to become web hosts themselves. Resellers could function, for individual domains, under any combination of these listed types of hosting, depending on who they are affiliated with as a provider. Resellers' accounts may vary tremendously in size: they may have their own virtual dedicated server to a colocated server. Virtual Dedicated Server: slicing up a server into virtual servers. each user feels like they're on their own dedicated server, but they're actually sharing a server with many other users. The users may have root access to their own virtual space. Dedicated hosting service: the user gets his or her own Web server and gains full control over it (root access for Linux/administrator access for Windows); however, the user typically does not own the server. Another type of Dedicated hosting is Self-Managed or Unmanaged. This is usually the least expensive for Dedicated plans. The user has full administrative access to the box, which means the client is responsible for the security and maintenance of his own dedicated box. Managed hosting service: the user gets his or her own Web server but is not allowed full control over it (root access for Linux/administrator access for Windows); however, they are allowed to manage their data via FTP or other remote management tools. The user is disallowed full control so that the provider can guarantee quality of service by not allowing the user to modify the server or potentially create configuration problems. The user typically does not own the server. The server is leased to the client. Colocation web hosting service: similar to the dedicated web hosting service, but the user owns the colo server; the hosting company provides physical space that the server takes up and takes care of the server. This is the most powerful and expensive type of the web hosting service. In most cases, the colocation provider may provide little to no support directly for their client's machine, providing only the electrical, Internet access, and storage facilities for the server. In most cases for colo, the client would have his own administrator visit the data center on site to do any hardware upgrades or changes. Clustered hosting: having multiple servers hosting the same content for better resource utilization. Grid hosting : relatively a new web hosting buzz, this form of distributed hosting is when a server cluster acts like a grid and is composed of multiple nodes. Being highly fault tolerant, this system is breaking new grounds when it comes to the network stability factor. Some specific types of hosting provided by web host service providers:
File hosting service: hosts not web pages but files Image hosting service Video hosting service Blog hosting service One-click hosting Shopping cart software
Hosting services limited to the Web:
Free web hosting service: is free, (sometimes) advertisement-supported web hosting, and is often limited when compared to paid hosting. Shared web hosting service: one's Web site is placed on the same server as many other sites, ranging from a few to hundreds or thousands. Typically, all domains may share a common pool of server resources, such as RAM and the CPU. A shared website may be hosted with a reseller. Reseller web hosting: allows clients to become web hosts themselves. Resellers could function, for individual domains, under any combination of these listed types of hosting, depending on who they are affiliated with as a provider. Resellers' accounts may vary tremendously in size: they may have their own virtual dedicated server to a colocated server. Virtual Dedicated Server: slicing up a server into virtual servers. each user feels like they're on their own dedicated server, but they're actually sharing a server with many other users. The users may have root access to their own virtual space. Dedicated hosting service: the user gets his or her own Web server and gains full control over it (root access for Linux/administrator access for Windows); however, the user typically does not own the server. Another type of Dedicated hosting is Self-Managed or Unmanaged. This is usually the least expensive for Dedicated plans. The user has full administrative access to the box, which means the client is responsible for the security and maintenance of his own dedicated box. Managed hosting service: the user gets his or her own Web server but is not allowed full control over it (root access for Linux/administrator access for Windows); however, they are allowed to manage their data via FTP or other remote management tools. The user is disallowed full control so that the provider can guarantee quality of service by not allowing the user to modify the server or potentially create configuration problems. The user typically does not own the server. The server is leased to the client. Colocation web hosting service: similar to the dedicated web hosting service, but the user owns the colo server; the hosting company provides physical space that the server takes up and takes care of the server. This is the most powerful and expensive type of the web hosting service. In most cases, the colocation provider may provide little to no support directly for their client's machine, providing only the electrical, Internet access, and storage facilities for the server. In most cases for colo, the client would have his own administrator visit the data center on site to do any hardware upgrades or changes. Clustered hosting: having multiple servers hosting the same content for better resource utilization. Grid hosting : relatively a new web hosting buzz, this form of distributed hosting is when a server cluster acts like a grid and is composed of multiple nodes. Being highly fault tolerant, this system is breaking new grounds when it comes to the network stability factor. Some specific types of hosting provided by web host service providers:
File hosting service: hosts not web pages but files Image hosting service Video hosting service Blog hosting service One-click hosting Shopping cart software
INTRODUCTION
A web hosting service is a type of Internet hosting service that allows individuals and organizations to provide their own websites accessible via the World Wide Web. Web hosts are companies that provide space on a server they own for use by their clients as well as providing Internet connectivity, typically in a data center. Webhosts can also provide data center space and connectivity to the Internet for servers they do not own to be located in their data center, called colocation.
The scopes of hosting services vary widely. The most basic is webpage and small-scale file hosting, where files can be uploaded via File Transfer Protocol (FTP) or a Web interface. The files are usually delivered to the Web "as is" or with little processing. Many Internet service providers (ISPs) offer this service for free to their subscribers. People can also obtain Web page hosting from other, alternative service providers. Personal web site hosting is typically free, advertisement-sponsored, or cheap. Business web site hosting often has a higher expense.
Single page hosting is generally sufficient only for personal web pages. A complex site calls for a more comprehensive package that provides database support and application development platforms (e.g. PHP, Java, and ASP.NET). These facilities allow the customers to write or install scripts for applications like forums and content management. For e-commerce, SSL is also required.
The host may also provide an interface control panel (e.g. cPanel, Plesk or others) for managing the Web server and installing scripts as well as other services like e-mail. Recently, Web.com holds many patents it claims cover broad methods for website building and web control panels. Hostopia, a large wholesale host, recently purchased a license to use that technology from web.com for 10% of retail revenues[1]. Web.com recently sued Go Daddy as well for similar patent infringement [2].
Some hosts specialize in certain software or services (e.g. e-commerce). They are commonly used by larger companies to outsource network infrastructure to a hosting company. To find a web hosting company, there are searchable directories that can be used. One must be extremely careful when searching for a new company due to the fact that many of the people promoting service providers are actually affiliates and the reviews are biased.
The scopes of hosting services vary widely. The most basic is webpage and small-scale file hosting, where files can be uploaded via File Transfer Protocol (FTP) or a Web interface. The files are usually delivered to the Web "as is" or with little processing. Many Internet service providers (ISPs) offer this service for free to their subscribers. People can also obtain Web page hosting from other, alternative service providers. Personal web site hosting is typically free, advertisement-sponsored, or cheap. Business web site hosting often has a higher expense.
Single page hosting is generally sufficient only for personal web pages. A complex site calls for a more comprehensive package that provides database support and application development platforms (e.g. PHP, Java, and ASP.NET). These facilities allow the customers to write or install scripts for applications like forums and content management. For e-commerce, SSL is also required.
The host may also provide an interface control panel (e.g. cPanel, Plesk or others) for managing the Web server and installing scripts as well as other services like e-mail. Recently, Web.com holds many patents it claims cover broad methods for website building and web control panels. Hostopia, a large wholesale host, recently purchased a license to use that technology from web.com for 10% of retail revenues[1]. Web.com recently sued Go Daddy as well for similar patent infringement [2].
Some hosts specialize in certain software or services (e.g. e-commerce). They are commonly used by larger companies to outsource network infrastructure to a hosting company. To find a web hosting company, there are searchable directories that can be used. One must be extremely careful when searching for a new company due to the fact that many of the people promoting service providers are actually affiliates and the reviews are biased.
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