What is dnslookup?
A DNS lookup is the process your computer uses to turn a human‑readable website name (like www.example.com) into the numeric IP address (like 93.184.216.34) that computers use to talk to each other over the internet.
Let's break it down
- You type a URL into your browser.
- Your computer asks a DNS server, “What IP belongs to this name?”
- The DNS server checks its records or asks other servers until it finds the right IP.
- It sends the IP back to your computer, which then connects to that address to load the site.
Why does it matter?
Without DNS lookups you would have to remember long strings of numbers for every website. DNS makes the web user‑friendly, speeds up connections, and lets website owners change servers without changing the name people type.
Where is it used?
- Every time you visit a website or use an online service.
- Email clients looking up mail server addresses.
- Apps that need to reach APIs or cloud services.
- Network tools that diagnose connectivity (e.g., ping, traceroute).
Good things about it
- Simplicity: users work with easy names instead of numbers.
- Flexibility: sites can move to new servers, use load balancers, or CDNs without breaking links.
- Speed: caching DNS responses reduces lookup time for repeat visits.
- Redundancy: multiple DNS servers provide fallback if one fails.
Not-so-good things
- Dependency on DNS servers: if they go down, you can’t reach sites.
- Security risks: attackers can spoof DNS responses (DNS poisoning) to redirect traffic.
- Privacy concerns: DNS queries reveal which sites you visit unless encrypted (e.g., DoH, DoT).
- Propagation delay: changes to DNS records can take time to spread, causing temporary outages.