> Do not use undelegated domain names like .lan, .home, .homenet, .network, nor should you make up your own domain name. ...why? My DNS server, my rules, no? Why should I feel obligated to follow ICANN? Obviously, I'll need to make changes if someone ever registers the domain with ICANN (and I want to access the ICANN version), but other than that...
The main issue is if it gets sold later, or assigned by RFC. As an example, more than one company I've worked for used .dev as a TLD for their dev environments, with local DNS to override it. Once google bought .dev, this meant that:
- we couldn't access anything Google put on .dev
- suddenly, all of our test sites had HTTPS forced, because .dev was HSTS preloaded by Google
The point here is that an unexpected change that you might not be aware is coming can break your setup in ways that are awkward to resolve - eg HSTS preloading means that you can no longer access non HTTPS endpoints unless you do it by IP and that leads to a frustrating afternoon - and it's inevitably always when you don't want it.
Like it or not, ICANN operates the DNS space. There's a proper way to get your own piece of this space, and you can run home or business networks under your own piece and you have a guarantee that no one will break you - because it's yours.
(edited for formatting)