DNS for Beginners

DNS Will Finally Make Sense After This

DNS for complete beginners, on a tiny private copy of the internet's DNS in our lab: our own root server, a .test top-level domain server, Ana's DNS server for shop.test, two resolvers and two laptops. Ana moves her shop's website to a new server, but her customer Ben still lands on the old one. We follow a lookup from the resolver to the root, the top-level domain and the authoritative server with dig +trace, take a DNS record apart, see caching make a lookup 273 ms then 0 ms, watch Ben's TTL run out, and redo the move the right way: lower the TTL first, wait, then switch.