DNS Motivations and uses

* The possibility to attribute a testuale name easy memorizzare to a serveur (as an example a situated World Wide Web) improves a lot the use of the service, in how much the human beings find easier to remember testuali names (while the hosts and the router are raggiungibili using numerical IP addresses). For this, the DNS is fundamental for the wide spread of Internet also between not technical customers, and is one of its more visible characteristics.
* It is possible to attribute more names to same IP address (or viceversa) in order to represent various services or functions supplied from a same host (or more host that distributes the same service. This flexibility turns out useful in many cases:
o In the case the serveur must replace the serveur that accommodates a service, or its IP address must be modified, is sufficient to modify record DNS, without having to take part on the client.
o I use much popular one of this possibility is the so-called one virtual hosting based on the names, one technical for which an endowed web server of a single interface of net and single IP address it can accommodate more situated web, using the alphanumeric address transmitted in header the HTTP in order to identify the situated one for which it comes made the demand.
o Using various names in order to refer to the various services it distributes to you from a host, it is possible to move a part of the services on an other host, and to move client on the this new host being modified its records in the DNS.
o Making to correspond more IP addresses to a name, the cargo of the client comes distributed on various serveur, obtaining an increase of the total performances of the service and a tolerance to the breakdowns (but it is necessary to make sure itself that various the serveur is always aligns to you, that is offer the same service exactly to the client).
* The inverse resolution is useful in order to identify the identity of a host, or in order to read the result of a traceroute.
* The DNS comes used from numerous technologies in little visible way the customers, in order to organize the necessary information to the operation of the service.