When operating promiscuously, the device will
learn ARP information from all ARP packets
received. When non-promiscuous, the device
will learn information only from ARP packets
addressed to the IP address of the device.
When operating in refresh mode, when it is
time for an entry to age out, the device
will refresh the entry by ARPing for it
again. Devices will thus stay in the ARP
table until disconnected, even if they are
not communicating via the router. In norefresh
mode, the entry will simply be aged out, and
refreshed only if traffic warrants.