ipmon(8) on FreeBSD
The text 9443ee8b9187, as FreeBSD 4.0-RELEASE shipped it.
monitors /dev/ipl for logged packets
Flags it lists
-
-F -
-N -
-O -
-S -
-X -
-a -
-f -
-n -
-o -
-s -
-t -
-v -
-x