Config is layered: built-in defaults, then the YAML file, then BFD_* environment variables, then CLI flags. Global defaults live under a 'defaults' mapping; per-peer settings are file-only. Includes config.yaml.dist and ScriptHookSink::with_script_dir so the hooks directory is configurable.
Can now establish and hold a session with BIRD, successfully detect Down
state, and call scripts on state change via an event dispatch engine.
Can't maintain a session with VyOS. I think it is calculating the timers
incorrectly, but don't trust my own implementation of course...
ktims