Where can I get info about /dev/arp parameters?

I'm looking for info about the tuneable parameters in /dev/arp....couldn't find any doc about them....any suggestion?

Thanks!

# ndd /dev/arp \?

arp_cleanup_interval          (read and write)
arp_publish_interval          (read and write)
arp_publish_count             (read and write)
arp_probe_delay               (read and write)
arp_probe_interval            (read and write)
arp_probe_count               (read and write)
arp_fastprobe_delay           (read and write)
arp_fastprobe_interval        (read and write)
arp_fastprobe_count           (read and write)
arp_defend_interval           (read and write)
arp_defend_rate               (read and write)
arp_broadcast_interval        (read and write)
arp_defend_period             (read and write)