DNS Explained – How Domain Names Get Resolved

3 months ago

DNS translates domain names into IP addresses, making it easier to access websites without memorizing IPs.
DNS is organized hierarchically: Root servers know TLD servers, which know domain servers, which know subdomains.
Common DNS record types include A (IPv4), AAAA (IPv6), CNAME (aliases), MX (mail), and TXT (text for verification).
TTL (Time To Live) determines how long DNS records are cached, affecting propagation speed when changes are made.
DNS resolution involves multiple steps: browser cache, OS cache, router cache, ISP resolver, root servers, TLD servers, and authoritative nameservers.
Resolvers (like Google's 8.8.8.8) fetch DNS records, while nameservers store them (e.g., Cloudflare, AWS Route 53).
DNS can be used for load balancing, failover, and geographic routing by returning different IPs based on conditions.
Debugging DNS issues involves checking and clearing caches (browser, OS) and using tools like `nslookup` and `dig`.

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