Explain the purpose of DNS and how it resolves domain names to IPs.
This question covers the Domain Name System functionality and resolution hierarchy. It tests understanding of internet infrastructure and lookup processes.
Why Interviewers Ask This
DNS is the backbone of internet navigation. Interviewers ask this to ensure you understand how clients locate servers efficiently. Knowledge of caching, recursion, and root servers is vital for optimizing network latency in global applications.
How to Answer This Question
Describe DNS as a phonebook for the internet. Walk through the resolution steps: local cache, recursive resolver, root server, TLD, and authoritative server. Mention caching mechanisms and TTL values. Briefly touch upon load balancing via DNS.
Key Points to Cover
- Domain to IP mapping
- Resolution hierarchy
- Caching mechanisms
- TTL importance
Sample Answer
DNS translates human-readable domain names into machine-readable IP addresses. The process starts with checking local caches, then querying recursive resolvers. If not found, the resolver contacts root servers, then TLD…
Common Mistakes to Avoid
- Skipping the recursive resolver step
- Ignoring caching benefits
- Confusing A records with CNAME
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