Man Pages in freebsd-manpages

Section 4freebsd: Special files

ipf.4freebsd

Packet filtering kernel interface

ipfilter.4freebsd

Introduction to ip packet filtering

ipl.4freebsd

Ip packet log device

ipnat.4freebsd

Network address translation kernel interface

opie.4freebsd

One-time passwords in everything

skey.4freebsd

One-time passwords in everything