|Nameserver lookup or NS Lookup is an easy tool for obtaining name server records for any domain name on the internet. NS is actually a record class of DNS, which is installed via a domain name hosting service. Whenever a visitor requests DNS record for a domain name, it checks the nameserver settings, and finally gets the desired response back from the DNS server.|
There are basically two types of nameserver that can be queried through DNS. The first one is the authoritative nameserver which is the one that resolves the names for you, i.e. you get to see names resolved by the server after you have logged in to the domain names server. Nameserver used as a reverse DNS service is different in that it not only resolves names but also stores information about DNS zone files stored in the DNS server. Name zone files are the DNS information about subnets, IP addresses and keywords.
As we know, both authoritative and reverse DNS service can be queried by DNS clients, but these kind of services store different data files. In case of reverse DNS lookups, the data files are stored in the nameserver's directory. As said earlier, when a DNS client requests for information about a domain nameserver, it first looks up the nameserver's directory to start the query. Once the query is successful, a response is sent to the client which contain list of results starting from the current query index and moving up to the top level.
Basically, DNS servers are built using the DNS protocol and the DNS client uses this protocol to access it. The DNS server is responsible for performing the functions defined in the DNS protocols. A DNS database maintains information about nameservers and hosts. The database stores such things as information about domain name, names, IP addresses and other DNS related resources. For accurate operation of the DNS system, these data files should be maintained in chronological order.
As we know, DNS nameserver translates or names domain name into IP address or IP addresses into names. The DNS system works by maintaining a list of CID records which are unique to each domain name registered. These CID records are stored in separate files inside the DNS server. The two types of records are, inetentiate domain name record and in existent domain name record.
There are many reasons why DNS servers are considered as authoritative. To understand this, you must know that when you type an IP address on your browser's address bar, the DNS server translates the IP address to a domain name which is located on its own server. On the other hand, a DNS server is authoritative only when it maintains a consistent catalog of nameservers for which it is responsible. This consistent catalog is maintained by free dns and some paid ones.
The domain name which you typed on your browser's address bar is actually the first piece of information which will be transferred to the DNS servers. Nameservers, on the other hand, are used for passing data from the DNS server to the clients. Another popular service is called as delegated DNS hosting. This kind of service allows the customers to register their nameservers with any hosting provider they want. They can also alter or modify the settings of the nameservers, if they want to. In addition, users can also change or add sub-domain names which is again, another way of making use of the DNS system.
Now that you know what is DNS server there is still a slight problem. There are times when people forget that they typed the domain name in the address bar and instead try to guess what the IP address is. This leads to getting the wrong IP address and a problem in trying to contact the domain name owner. To avoid this kind of problem people should keep track of the DNS records on their mail server. This way they can refresh the information every time they check their mail. Remember, an IP address alone does not point to a domain name, so if you remember the DNS domain name and you know the IP address but you still cannot reach the domain owner it could be because the mail server has forgotten to update its DNS records or the owner of the domain name may be using an alternate address which is not his or hers.