Question

Explain about the name server?

Answer 1

1. The information which needs to be stored in the Domain namespace is quite large. A 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 subdomains
3. DNS also allows domains to be further divided into subdomains. By this, the solution to the problem is obtained and the 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 translates 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 worldwide usage, so plenty of servers are used in a hierarchical manner.
8. Name servers do the important task of searching the domain names. While you searching a website, the Local Name server (provided by ISP) ask the different name servers until one of them find out your Answer. 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:

1. Root Name Server- A top-level server which contains entire DNS tree, maintained by ICANN. There are 13 servers.
2. Primary/Master Name Server- 
   It contains zone resource records. These records are updatable by domain name holders such as organizations.
3. Secondary/Slave Name Server- 
   It contains a copy of primary server files. This server has no authority to update, but to reduce the workload of the master server by sharing the queries.