SAGARFIVE

DNS

DNS Server Types

These are used to resolve DNS query(domain→ ip) one by one if early stage fails goes next


(i). Recursive server :
DNS Database maintained by ISP
It takes DNS queries from web browser , directly gives IP, if it’s already visited (Cached) ,if it’s not available at local database then sends request to next level server.


(ii). Root Name server :
DNS Database maintained by ICANN
here you can find name servers(Database tables – maintained ICANN) , next query moves to next server

ICANN : The Internet Corporation for Assigned Names and Numbers is an American multistakeholder group and nonprofit organization responsible for coordinating the maintenance and procedures of several databases related to the namespaces and numerical spaces of the Internet, ensuring the network’s stable and secure operation.

(iii). TLD server :
DNS Database maintained by IANA
The root server directs the query based on the TLD — the .com, .edu or .org in the URL.
IANA : Internet Assigned Numbers Authority,
If DNS Query find an IP Related to domain, it send to browser

(iv) Authoritative name server :
It check at TLD Subdomain Level
An authoritative server is the authority for its zone. It queries and is queried by other name servers in the DNS. The data it receives in response from other name servers is cached. Authoritative servers are not authoritative for cached data.