| When you want to buy or sell a domain name or change the IP address of your domain name there are several steps you need to take. However there are two different types of servers which are used for these purposes. A name server is simply a computer that returns an IP address whenever given a domain name with the request for information. This IP address is actually the location of the domain on the Internet. In some cases name servers can also be referred to as DNS servers (and vice-versa) since they basically do the same function; they return the IP location of the domain for query. There are basically two types of domain lookups, static and dynamic. A static domain lookup requires information to be entered into a data base (typed or otherwise), the server will then search it and return results for that domain name. If no name is entered the search engine will return a "zero" result. If you enter the domain name and there is no record for it then the domain name is considered dynamic, and you will need to provide your own information in order to obtain the full address including the sub-domain name and website. The problem with a static domain lookup is that since you cannot modify the details sent by the server, if you change your IP you will not have your old record changed and your domain name will be lost. Dynamic domain name lookups are typically used by online retailers who wish to associate their domain names with an e-commerce site. This allows customers to click on a shopping cart and enter their credit card information and the store will have the ability to track who has visited the site through the credit card. In the case of e-commerce this means that customers can type in an address and be matched with an e-commerce website that sells the item they have purchased. This option is often much more convenient than having to remember each individual customer's IP addresses. Another example of a domain name system is the regular Reverse DNS. When you are typing in an address in the search engines or on a web page you will be directed to a website that has a reverse dns lookups listing. This reverse dns lookups system is similar to that of a phone book. When you enter an address in you will be directed to a website that has information on that IP Address. If you are familiar with using the telephone book then you will be comfortable with this. With the reverse dns system you are directed to a website that keeps detailed records of every website that has registered with them. The domain name system also includes a feature called the recursive dns query feature. With the Recursive DNS a domain name is matched with an IP address. If the domain name resolves to an IP Address and it is found that the IP Address is already owned by someone, then the domain name will be an option on a reverse dns lookup. The domain name servers function as a filter for all requests to a domain name system. In the normal operation of the domain name system when a client requests a name from the system they are matched against a list of nameserver queries. The server then looks up the requested domain name and determines if it is available and in the database. If the name is not available it is rejected and a new request is sent to the nameserver. These are basically two separate types of name servers. The second type of server is a rewrite algorithm. The domain name server uses this algorithm when reading back the response from the nameserver. If it determines that the requested domain name is not in the cache then it will try to make another connection to the nameserver until the information is successfully read. If it can not read it's response then it will return a'servertool' error which is intended for debugging purposes. Some of these name servers allow domain names with slashes to be resolved by normal queries. This can be very handy if you own multiple sites. They also allow you to control access to certain IP addresses and change them whenever you wish. You can even restrict directories from being able to resolve domain names. This is useful if you own multiple business sites but don't want employees to be able to access their home email account from their work site. It is possible to set up your own name servers if you have the resources to do so. |