Chapter 1
Why DNS?
Names beat numbers
Computers route packets using IP addresses — long strings of digits, and IPv6 turns them into hexadecimal soup. People aren't great at memorizing those. DNS is the phonebook of the internet: a global, distributed system that turns memorable names like wikipedia.org into the IP addresses machines actually need. It runs silently behind nearly every request you make.
Without DNS
2606:4700:4700::1111
Type a name. Watch what happens.
Domains you'd need to memorize
wikipedia.org
2620:0:863:ed1a::1
github.com
140.82.121.4
stackoverflow
2606:4700::6810:1c25
cloudflare.com
104.16.132.229
youtube.com
2607:f8b0:4005:80d::200e
amazon.com
205.251.242.103
reddit.com
151.101.65.140
nytimes.com
2606:4700:7::a29f:9d44
With DNS
wikipedia.org
Type a domain — DNS does the rest.
Human memory · rough tally
Domains we can recall~50
Raw IPs we can recall~3
Key takeaways
- IP addresses (especially IPv6) are too long for humans to memorize
- DNS maps human-friendly names to machine-friendly IP addresses
- Without DNS, every site would have to be visited by raw IP
- It is the silent translator behind nearly every internet request