Q59.Marks: +2.0UGC NET Paper 2: Computer Sc 23rd August 2024 Shift 1
Arrange the following steps in a proper sequence for the typical process of a DNS query:
(A) Query authoritative DNS Server
(B) Query local DNS Server
(C) Local DNS Server Check Cache
(D) Query root DNS Server
(E) Query TLD DNS Server
Choose the correct answer from the options given below:
1.(A), (C), (E), (B), (D)
2.(E), (A), (C), (B), (D)
3.(A), (B), (C), (D), (E)
4.(B), (C), (D), (E), (A)✓ Correct
Solution
The correct answer is (B), (C), (D), (E), (A).
Key Points
Query local DNS Server: The initial step in a DNS query is to query the local DNS server. This is typically the DNS server provided by your ISP or configured on your network.
Local DNS Server Check Cache: The local DNS server first checks its cache to see if it already has the IP address for the requested domain name.
Query root DNS Server: If the local DNS server doesn't have the information, it queries a root DNS server. Root DNS servers are the highest level in the DNS hierarchy.
Query TLD DNS Server: The root DNS server responds with the address of a TLD (Top-Level Domain) DNS server, which is queried next. TLD servers handle top-level domains like .com, .net, etc.
Query authoritative DNS Server: Finally, the TLD server responds with the address of the authoritative DNS server for the specific domain, which is queried to obtain the final IP address.
Thus the correct answer is (B), (C), (D), (E), (A).
Additional Information
The Domain Name System (DNS) is a hierarchical and decentralized naming system for computers, services, or other resources connected to the Internet or a private network.
DNS translates more readily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols.
DNS queries can be recursive or iterative. In a recursive query, the DNS server will perform all the necessary lookups and return the final IP address to the client. In an iterative query, the client performs each step of the lookup process itself.
