FWIW, the dnsmasq log shows that the hub started all this yesterday at 9:04:07am, 3 minutes after it had renewed its DHCP lease.
It stopped this morning at 07:52:57 immediately after the hub had refreshed its DHCP lease, and about 12 hours after the last time I rebooted the hub.
I rebooted the hub numerous times between these two events, and the DNS PTR lookups started back up each time after the hub restarted.
Looking back at the logs, it appears that this spike in DNS requests has been occurring about every 3 days, but only running for about 12 hours...(perhaps because I didn't reboot the hub on the prior occurrences).
It would thus seem that there is some specific logic that turns this behavior on and off for some reason...
