Name Servers:
1. The information which needs to be stored in Domain name space is quite large. Single system would be inefficient and insufficient to store such a huge amount as responding to requests from all over the world. It also becomes unreliable because in case of any failure the data becomes inaccessible.
2. The solution to this problem is to distribute the information among many computers. The best way to do that is to divide the entire space into many domains and sub domains
3. DNS also allows domains to be further divided into sub domains. By this, the solution to the problem is obtained and hierarchy of servers is also maintained.
4. Name servers store the data and provide it to clients when queried by them. Name Servers are programs that run on a physical system and store all the zone data.
5. Name Server is a main part in the Domain Name System (DNS). It translate the domain names to IP addresses.
6. Name server contains the DNS database which consists of domain names and their corresponding IP addresses.
7. There is a need to store large number of domain names for the world wide usage, so plenty of servers are used in the hierarchical manner.
8. Name servers do the important task of searching the domain names. While you searching a website, Local Name server (provided by ISP) ask the different name servers until one of them find out your Answer:wer. At last it returns IP address for that domain name.
Types of Name Servers
There are three types of Name Servers which control the entire Domain Name System:
(i) Root Name Server – top level server which contains entire DNS tree, maintained by ICANN. There are 13 servers.
(ii) Primary/Master Name Server – contains a zone resource records. These records are updatable by domain name holders such as organizations.
(iii) Secondary/Slave Name Server – contains a copy of primary server files. This server has no authority to update, but reduce the workload of master server by sharing the queries.
