How does dns work?

Question

Domain Name System

My friend and I have a website. We transferred it to another hosting and changed the DNS records. His site soon started working, but I didn’t, and he advised me to restart the Internet, backing it up with this argument "After the Internet is restarted, packages are re-registered on the DNS server, with the packages updated, the site registry for the user is updated." I disagree with this argument and would like to know if this statement is true.

Answer 1

DNS resolution goes something like this:
local resolver + cache -> recursive resolver (the provider's DNS server specified in the connection properties or Google's DNS server) -> zone server (on which you made changes).
However, both the local resolver and the provider's recursive resolver can cache previous responses, so changes are not immediately visible. The cache time is determined by the TTL parameter, which can be set to the default for the zone or separately for each entry. Before changing records, TTL is usually reduced in advance so that new records work faster.
Whatever you do with the local machine will not affect the recursive resolver cache.
However, there is also a local cache, which usually caches responses for a short time independent of the TTL. It can indeed be reset when the connection is re-established. However, it is much easier to do this with the command
on Windows
ipconfig /flushdns
on Linux
nscd -i
As a rule, this helps in cases of corporate DNS, with changes in the corporate zone, when the functions of the zone server and the recursive resolver are performed by the same server, so the recursive server does not caches the resolved entry and gives it directly from the zone, and caching occurs only in the local resolver.

Answer 2

Some providers may not update their DNS for weeks. And this threatens that after changing the DNS records for the domain from the phone (without wifi connection), the site will open, and from the home computer (connected, for example, to a local Internet provider in the Moscow region), the site will still be available with old DNS records.
Here, either edit your hosts, or just wait.

Answer 3

No. Your ISP's DNS has cached the previous address, how updating the Internet will help here is unclear.