# ~/.ssh/config
Host home
  HostName relay.example.com
  User d3k5fia7m4us73ehblug
  Port 2222
# ~/.ssh/known_hosts, once per device
[relay.example.com]:2222 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAICiecex8Dq718eSe1CCLgLvDmI7AagvCtax7brPFWkh4
