|A domain name is the portion of an URL which identifies a specific website. It is a part of the address, which is a part of the internet protocol. A DNS server is responsible for maintaining the DNS records of various domain names, and the zone file contains information about these names. The DNS servers are usually the same on all machines that connect to the internet, but there is flexibility in this and different types of nameservers are available.|
Nameservers are also known as domain name servers or, more commonly, as DNS servers. They are also known as the system domains, or addresses. The nameserver should be able to provide logical addresses for the client machines. These are needed in order to configure the DNS settings on the client machines, and a different nameserver can be used when the client machines are connected to a different network.
A DNS server is programmed to accept requests from clients, and it will respond to them with a query message. In return, the DNS server creates a list, or zone file, of names associated with the domain name that was requested. Each name in the zone file corresponds to an IP address. The DNS server and the zone files are usually updated periodically, and this is done by communication between the client machine and the DNS server. Updates can be manually initiated by the owner of the domain name or by an administrator who works on the DNS system. Some DNS providers provide automated updates to the zone files; however, the client machines must periodically read and update the zone files themselves.
There are several types of name servers, and their purposes are diverse. For example, some name servers are configured to provide dynamic DNS services to a user. This means that the name of a domain is resolved whenever a user types an IP address into an Internet browser. Another type of name server is a static name server; it can only be queried or registered by an IP address. A third type of name server is an IP-based name server, which registers or queries only specific IP addresses for domain name registration purposes.
Many businesses use domain name servers to facilitate smooth customer access to the company website. For example, a business may have several different websites that point to the same main website. If each of these websites were operated on its own domain name, then each would have its own individual name server, and customers would need to contact all of these servers for information regarding a particular domain name.
One way to overcome the problem of too many server names is to implement a central DNS service that serves as a reverse DNS service. Instead of requesting information about a domain name, the DNS service returns a predetermined list of domains matching the IP address entered. In other words, when someone types in the domain name, the server returns a list of all the DNS servers that currently have information on that domain name. The DNS server then determines which name servers should contain the requested information. If there are no servers matching the domain name, the DNS server returns a DNS error message. If the domain name is not available, the DNS server returns an error code, indicating that there is an error in the operation.
Another way to avoid too many domain name servers is to use name shadowing. When you register a domain name with your domain name provider, you are given the option to register your name as many names as you want. In theory, you could use all of your domain name servers to register all of the names you desire. However, most providers do not do this because they would have to add a fee to cover the extra services, and it would take them too long to add and remove names as needed. Instead, they allow you to register up to N number of name servers with them, and since each name has its own IP address, they can always return a match for the domain name in question.
Of course, the most important part of the name server is the IP address. This address, which is only visible to the relevant names within the network, is what the visitor actually sees when they connect to your site. The domain name, of course, is only registered in your name server; and the IP address is visible to anyone on the internet, so even if you have registered many names that eventually become registered as unused, the IP address still remains the same, making it vulnerable to misuse. It is for this reason that you should use caution when deciding how many name servers you need to use for your website.