Every listener
nobody asked for.
A list of open ports is not useful on its own — every host has some. What is useful is knowing which of them no application on that host ever needed. PathMRI knows, because it already knows what the host is supposed to run.
Triage, not a list
What is actually listening
Per host: the port, protocol, process and PID, the service behind it, the listening address and the direction — with when it was first and last seen.
Against the applications assigned
The app mapping that drives connectivity checks also says which ports are expected. A listener no assigned application accounts for stands out instead of being lost in a list.
Approve what belongs
Learning mode turns a host's current listeners into an approved baseline in one pass, and recommends anything in use that the application library does not yet cover — with a tip on how to catalogue it.