which files are these guys talking about?

# ipf -v -f /etc/ipf.conf
open device: No such file or directory
[pass in proto tcp/udp all]
pass in proto tcp/udp from any to any
ioctl(SIOCADDFR): Bad file descriptor
[pass out proto tcp/udp all]
pass out proto tcp/udp from any to any
ioctl(SIOCADDFR): Bad file descriptor

#ipnat -f /etc/ipnat.conf
open: No such file or directory

There are no /dev/ip* files
on my system that the man pages talk
about - how do I get them?

thanks.
-ray