I've noticed that Interfaces: Neighbors: Discovery is working well in the latest 26.1.2 release.
I briefly tested the feature when it first debuted in January, and I've noticed that those original entries are still present in my Discovered Hosts. Because I am almost entirely IPv6 locally—and thanks to IPv6 Privacy Extensions—my list has ballooned to nearly 700 entries on a relatively small network.
Does the hostwatch database have a mechanism to automatically age out/purge stale entries? Or is manual maintenance required to keep the list from growing indefinitely?
I had a similar question (https://forum.opnsense.org/index.php?topic=50590.msg259799#msg259799).
Looks like there's no expiration policy at the moment.