The mesh's own addresses come from placement (each node's private address and its endpoint); who holds
node-intrusion-prevention, from seat-holders; who is heard, from the watchman's presence. Each heard holder is asked
seat:node-intrusion-prevention.banned@<node>, all at once. The finding is the controller's: machine.<node>.bans-the-mesh,
urgent, the same summary and words. A heard holder that does not answer makes the probe fail to run, never pass.
Rows in TestTheBusProbes; the manifest reads and invokes what the code does.