People always forget about ZeroTier's network flow rules. In a little text file/field, you have a full-on software-defined networking appliance, with filters on any kind of Layer 3-4 information, and a capability model. You could regulate a medium corporate network in about 50 lines, giving people capabilities as required or segmenting areas with tags. And it would work exactly the same whether laptops were inside the building or not. And you can do mad stuff like 'copy all TCP traffic with dport X to some machine running tcpdump'. The whole thing is a dream. I love it.

I personally use it as a replacement for AWS VPN Gateway using a ZT managed route and a couple of VPC route table entries. I detail that setup in my ZeroTier Terraform plugin: https://github.com/cormacrelf/terraform-provider-zerotier

How we moved to Google Cloud using Consul and ZeroTier with zero downtime | https://news.ycombinator.com/item?id=15548642 (Oct 2017)

I haven't looked at ZeroTier since they made those feature additions. I'll have to check them out.

EDIT: Just did. This[1] is amazing.

[1]: https://www.zerotier.com/manual.shtml#3_4

This. Performance is superb, and the connections are direct. Stable, super simple.

Highly underrated and too much under the radar afaik