Life of a sysadmin

Or: hand roll a ngrok with protonvpn port forwarding for shenanigans

A story of frantically rescuing a deployed headless server, where I forget to statically assign an IP address. It just won’t have network connection. No SSH. No fixie. Except there is nothing saying a DHCP server has to be running on the router or gateway. So, just install and configure kea (or a DHCP server of your choice) on any other computer on the network, reboot the server in question, and voilà! SSH to your hearts content. ...

Note this intended for relative networking novices, so I will try to explain every term used. Skip over them if you find it verbose. If you don’t care about anything else and just wants to replicate my setup for your home server, go to this section. Read the TL;DR’s in there if that section alone is too long for you too. Motivation Virtual mesh networking software, like Tailscale, ZeroTier, tinc, Hamachi and else, practically1 cannot establish a direct/p2p connection between a machine on the SJSU wifi and a machine somewhere else, running on a common residential internet. This situation is an example of a hard-NAT to easy-NAT connection (I’m using terminology from Tailscale’s article on NAT traversal). I really only use Tailscale, so that’s what I’m concerned with here. ...