ndp(8) on FreeBSD
The text af07d1866b7f, as FreeBSD 11.0-RELEASE shipped it.
control/diagnose IPv6 neighbor discovery protocol
Flags it lists
-
-A -
-H -
-I -
-P -
-R -
-a -
-c -
-d -
-f -
-n -
-p -
-r -
-s -
-t