There is no doubt that computer networks, the internet (heard of it?), has changed the way that we live our lives. It started out very simply as a military experiment, which quickly began to see use within communities of researchers at different universities. As the internet grew, more and more people had access to this massively expanding repository of the world’s information. It's obvious that the initial plan for the internet wasn't to support this many connected machines (don't get me started on IPv4...), nevertheless, the internet itself is generally considered a good thing.
The problem with the seemingly never-ending expansion of the internet is somewhat paradoxical: a goal of the internet is to house the worlds information, yet a lot of that information shouldn't be on the internet. Consider a typical software company, they have a database server along with a few application servers which serve requests for their customers. Application servers and database servers are networked together, each of which are (typically) assigned a public IPv4/IPv6 address and put behind a firewall to prevent unauthorized connections. Have you figured out the issue yet? We put machines (possibly containing extremely sensitive data) on the public network, then try and patch up the holes with virtual duct tape. Then for some reason, we're surprised when vulnerabilities are found leading to the personal information of 147.9 million people being exposed (cough Equifax cough).
The solution to this problem is simple: some (if not most) machines shouldn't be accessible via the public internet. This really isn't a breakthrough as cloud computing providers have been pushing for this for a while now with VPC systems, and VPN technologies. The concept is relatively simple - small, self-contained networks which require authentication to join, meaning once you're inside, communications and data are private by default. In essence, what I'm trying to get at is this idea of a personal (or corporate) internet. Inside this personal internet, you're the boss, and you can control who joins this network, and who can talk to who within it.
At that, we reach the point of this (rant). Enter Tailscale - a startup I'm rather fond of, and who I have been a power user of for a while now. Tailscale lets you easily make your own personal internet, for free in most cases. It's a weird paradigm shift, since inside this internet, you must actively work to make your applications insecure rather than the other way around. All traffic is encrypted and uses P2P as much as possible (DERP servers are used when P2P connections aren't possible - essentially an encrypted packet relay, nothing special). For a fun anecdote that isn't condoned by my employer, I setup my work machine at the office to my personal Tailscale network, and was able to tunnel directly into the machine from my house, without being connected to any of the corporate VPN nodes (presumably through many firewalls / NATs). Pro tip - using a P2P connection for RDP sessions is much preferred over a VPN-proxy onto the corporate network, just don't tell IT.
On the topic of my employer (who makes some epyc gear), it's worth mentioning that adopting Tailscale would be a great move for the company. Right now, we have 17 VPN servers worldwide which allow us to connect to the corporate network. If we're not in the office, any connection we make to another server inside this network has to be through one of these VPN servers, which certainly introduces some difficulty given that most of our 11,400 employees are working at home due to COVID-19. Obviously, productivity is impacted by the load on these servers, which leads to RDP sessions being quite sluggish when connecting to our work machines. A Tailscale network would alleviate most (or all) of our networking problems, since any employee given access to the network would be able to make a direct P2P connection (for the most part) to any other machines on the network, if allowed to do so by the company set access policies. In addition to this, the company would also have full observability into the access logs of different machines, which could help protect sensitive information on the network. You could also say that it would be worth ryzen to the occasion (I'm sorry for that one).
Before I started at my current employer, I did two internships at a YC-backed home security company, which primarily made smart home cameras, video doorbells, etc. In this role, I primarily focused on live video streaming (bidirectional streaming between home IOT device and users smartphone), and let me tell you this: with a few new features (notably the ability to pre-authorize clients to connect to a network), Tailscale would've been a game changer. Latency was important (ex. it's important that users are able to have real-time conversations with people who have rung their doorbell), and the ability to easily make secure P2P connections between our servers and our cameras would've made my job 100x easier. Forget any NAT traversal systems, hole punching, or any other dirty networking tactic, it would all have gone away with Tailscale.
So yeah, with my experience at both an IOT startup and a major corporation with severe networking issues, I think I'm uniquely qualified to rant about how great Tailscale is. It's a surprisingly simple idea, let people create mini sub-internets that they control, and Tailscale has done an amazing job making this a reality. I couldn't imagine not using Tailscale for my daily work, whether it is SSHing into my home servers from anywhere or exploiting the fact that I own the network to do cool distributed systems work.
If you want to get started with automatic peer discovery with Tailscale, I've open sourced a little bit of code to help out with this! You're welcome.