ipmon(8) on FreeBSD
The text 901f8fe16124, as FreeBSD 11.2-RELEASE shipped it.
monitors /dev/ipl for logged packets
Flags it lists
-
-B -
-D -
-F -
-L -
-N -
-O -
-P -
-S -
-X -
-a -
-b -
-f -
-n -
-o -
-p -
-s -
-t -
-v -
-x