I wrote a book that will teach you everything you need (and quite a bit you don’t) about domains, DNS, and TLS certificates. It’s available today and you can buy it right here.
While writing the book, I learned heaps of information about how the internet works at the DNS level. Most of that information made it into the book, but there are a few interesting bits and pieces that I couldn’t find a home for.
Here’s a grab-bag of facts I’ve collected over the course of writing the book. Some of these might not make a ton of sense if you’re not familiar with DNS. If that is the case, I have a great book recommendation for you.
Every top-level domain
Ever want a full list of all registered TLDs? Here it is. Note that these aren’t all available for registration, and some probably never will be. I doubt .apple or .google will be available to the general public any time soon. There are also certain country TLDs that aren’t available like .aw or .gw.
There’s not much rhyme or reason to why some TLDs are available and some aren’t. Maybe they’re not set up to take registrations, maybe they don’t want anyone outside of their country to snatch up domains for non-country purposes. If these TLDs are ever available, the registry gets to decide when, and how,
Domain registration stats
Registries send a report to ICANN at the end of every month. The reports (found here) are big spreadsheets that contains information like, how many domains were registered, renewed, transferred, etc. by each registrar. Ever been curious how many .club domains were registered in March of 2001? The answer is “none” because
.club didn’t exist until May of 2014. But you can get all the information on that TLD since then.
Become a registrar
If you ever wanted to run your own domain registrar like Hover or Gandi, it's… actually somewhat daunting to set up. All the steps are outlined over at Verisign. For example, you have to pay ICANN a $3,500 non-refundable fee and prove that you can handle the huge amounts of cash you’ll get as a domain registrar.
How domains are priced
This quora post outlines the process of how a
.com domain can cost around $10, but others can be priced in the thousands. (I’m looking at you .car.) In summary, registries (companies that own a TLD) sell domains in bulk to registrars (companies that sell domains to the general public). They can set whatever price they want, but first have to get ICANN to sign off on it. ICANN doesn’t decide prices, but they want to encourage a healthy market.
After registrars know the bulk price, they can price individual domains however they want so customers like us buy them. Prices change by the same process: a registry negotiates with ICANN, registries sell in bulk to registrars, registrars sell individual domains to us.
Public-key encryption is only lightly used
When you visit a site with a TLS certificate (think
https), your browser and the site set up a secure connection. All traffic from then on is encrypted and can only be decrypted by you and the website. The technique used to set up the encrypted communication is called public-key encryption.
A dirty secret in the encryption world is that public-key (also called asymmetric) encryption is only used at the start of an encrypted transaction to transfer a key for symmetric encryption, which is much faster.
Asymmetric encryption is still very important. Without transferring that symmetric key, encryption would either be slow or nonexistent, but I used to think public-key encryption was used for all communication on secure websites.
Coolest organization name
Finally, the coolest name for a standards organization goes to: the Internet Engineering Task Force. They publish many RFCs that have set standards since the Internet’s debut. They even set standards for the pre-Internet ARPANET.
While the RFC documents can be a bit dry, there have been a few humorous publications over the years.
If you enjoy learning this kind of thing, check out the book. It covers a lot of similar subjects, but in much greater depth. You’ll learn how to use command line tools to debug a domain, create TLS certificates for your website, and solutions to common scenarios like domain transferring or connecting to an external service. If you’ve ever tried to register or maintain a domain and been totally confused, you’ll love it.