> It would be a pity to throw away perfectly good information, although
> the effort involved may be greater than the nett gain.  Perhaps after
> an expiry period?  I'm thinking of a little hysteresis.

This feels like overengineering.

We're talking about arp entries here, which are inherently epemeral.
The system throws them out at least once every 10 minutes even if
they're in use..

					- Bill