Domain Name System (DNS) is like the internet’s phonebook. It translates human-friendly domain names (e.g., www.upsc.gov.in) into IP addresses (e.g., 164.100.94.59) that computers use to identify each other on a network.

Without DNS, we would have to memorise long numeric IPs for every website.

How DNS works

User enters URL in browserDNS Resolver checks if IP is cached locally; if not, queries startRoot DNS Server directs to Top-Level Domain (TLD) Server (e.g., .in, .com)TLD Server points to Authoritative Name Server for that domainAuthoritative Server returns IP addressBrowser connects to that IP → loads the website

Think of it as a hierarchical, distributed database maintained globally

Types of DNS records (important for tech + security questions)

A record → IPv4 address mappingAAAA record → IPv6 address mappingCNAME → Alias mappingMX → Mail server addressTXT → Verification & security info (SPF, DKIM)

Analytical importance (Civil Services perspective)

AspectAnalytical significanceGovernance & policyManaged globally by ICANN; critical for internet governance debates.Digital infrastructureBackbone of online services; impacts e-governance, digital economy.CybersecurityTarget for attacks like DNS spoofing, cache poisoning, pharming.Data sovereigntyCountries demand local DNS root servers to avoid foreign control.Service continuityDNS failures can paralyse entire sections of the internet.

Critical viewpoint

Centralisation risk – Although distributed, DNS root servers are few (Rs 13 logical root server clusters); potential geopolitical chokepoints.Vulnerability to attacks – DNS spoofing can redirect traffic to malicious sites, threatening cybersecurity & citizen trust.Dependency on US-based ICANN – Raises data sovereignty concerns for countries like India.Censorship potential – Governments can block sites at DNS level, which may conflict with freedom of expression.Lack of encryption – Traditional DNS queries are unencrypted; newer standards like DNS over HTTPS (DoH) and DNS over TLS (DoT) aim to fix this.

Relevance in India

Digital India & BharatNet expansion → needs robust DNS infrastructureNational Internet Exchange of India (NIXI) → manages .in domainCERT-In & MeitY initiatives → secure DNS practices for government websitesPush for local DNS root servers to improve speed, security & sovereignty