DNS

TL;DR Troubleshooting:

ping www.google.com
ping 8.8.8.8
- Did 8.8.8.8 return results -- but using the domain name www.google.com return errors? Congrats! You've got DNS issues!
Can you ping some rando website you've not visited before now? (lookin' at you yahoo.com)
Does the issue persist if you connect to a VPN, Mobile Hotspot, or use your 4G/5G Connection from your phone while your Wireless is turned off?
Is the issue different in a different browser?
- Does the issue persist in an Incognito Session?

`dig`

dig +short heretic.dev - Returns DNS Query output, minimal spam.
dig +trace +short heretic.dev - Returns DNS Results for each path taken en route to the host.
dig +short @8.8.8.8 heretic.dev - Specifies an alternative DNS Server for queries.

`nslookup`

nslookup heretic.dev
nslookup -debug heretic.dev
nslookup -debug heretic.dev 8.8.8.8

`host`

host heretic.dev
host heretic.dev 8.8.8.8

Misc

Change the local DNS to a different DNS Server.
- Here's a quick and dirty list of some public DNS Servers you can use to troubleshoot:

IPv4:

Google DNS:
8.8.8.8
8.8.4.4

Cloudflare:
1.1.1.1
1.0.0.1

Quad9:
9.9.9.9

OpenDNS:
208.67.222.222
208.67.220.220

IPv6: Don't touch it. But if you have to:

Google:
2001:4860:4860::8888
2001:4860:4860::8844

Cloudflare:
2606:4700:4700::1111
2606:4700:4700::1001

Quad9:
2620:fe::fe

OpenDNS:
2620:0:ccc::2
2620:0:ccd::2

A crash course in DNS:

DNS (Domain Name System) translates your device(s) human readable hostname into a machine readable IP Address.
Every networked device, no matter how small, interacts with DNS in some way.
If you're reading this - something is probably interacting with DNS in a negative way.

Bottoms Up 🍻

Start from the bottom, and work your way up.
- (Remember Drake? 😬️)
A general rule for systems during a conflict: Whatever's closest to the user wins...
- This is to say if there's a conflict in DNS, or almost ANY network wide configuration, the machine will defer to what it knows to be the most true
- ...which is itself.
  - "Always conduct yourself with the confidence of your laptop's DNS Resolver during outages." -

`localhost` will remember that...

Your local device (laptop, phone, the espresso machine, whatever) all have a built in DNS Resolver. It listens on a loopback address which by default is 127.0.0.1 on most systems and assigns itself the name localhost.
If you interact with heretic.dev your local DNS will go out onto the mean streets of the internet, fetch the IP Address of the server that hosts the domain, and take you there. To avoid unnecessary trips your local DNS will remember the DNS Record for you so that it doesn't have to go ask mom and dad where to find it.
If this address changes - your machine will SHOULD go out and fetch the new address for you. But - if it's been less than ~24 hours, most DNS servers will assume there hasn't been a dramatic change and serve you a stale record.

The Grimoire 📖