.TH IPF 1
.SH NAME
ipf - alters packet filtering lists for IP packet input and ouput
.SH SYNOPSIS
ipf [-AEDIsnovdrzZ] [-l <block|pass|nomatch>] [-F <i|o|a>]
-f <\fIfilename\fP> [ -f <\fIfilename\fP> [...]]
.SH DESCRIPTION
.PP
\fBipf\fP opens the filenames listed (treating "-" as stdin) and parses the
file for a set of rules which are to be added or removed from the packet
filter rule set.
.PP
Each rule processed by \fBipf\fP
is added to the kernels internal lists if there are no parsing problems.
Rules are added to the end of the internal lists, matching the order in
which they appear when given to \fBipf\fP.
.SH OPTIONS
.IP -A
set the list to make changes to the active list (default).
.IP -E
Enable the filter (if disabled).  Not effective for loadable kernel versions.
.IP -D
Disable the filter (if enabled).  Not effective for loadable kernel versions.
.IP -F
this option specifies which filter list to flush.  The parameter should
either be "i" (input), "o" (output) or "a" (remove all filter rules).
Either a single letter or an entire word starting with the appropriate
letter maybe used.  This option maybe before, or after, any other with
the order on the command line being that used to execute options.
.IP -d
turn debug mode on.  Causes a hexdump of filter rules to be generated as
it processes each one.
.IP -f
this option specifies which files
\fBipf\fP should use to get input from for modifying the pack filter rule
lists.
.IP -I
set the list to make changes to the inactive list.
.IP -l
Use of the \fB-l\fP flag toggles default logging of packets.  Valid
arguments to this option are \fBpass\fP, \fBblock\fP and \fBnomatch\fP.
When an option is set, any packet which exits filtering and matches the
set category is logged.  This is most useful for causing all packets
which don't match any of the loaded rules to be logged.
.IP -n
This flag (no-change) prevents \fBipf\fP from actually making any ioctl
calls or doing anything which would alter the currently running kernel.
.IP -o
Force rules by default to be added/deleted to/from the output list, rather
than the (default) input list.
.IP -s
swap the active filter list in use to be the "other" one.
.IP -r
remove matching filter rules rather than add them to the internal lists
.IP -v
turn verbose mode on.  Displays information relating to rule processing.
.IP -z
for each rule in the input file, reset the statistics for it to zero and
display the statistics prior to them being zero'd.
.IP -Z
zero global statistics held in the kernel for filtering only (this doesn't
affect fragment or state statistics).
.DT
.SH SEE ALSO
ipfstat(1), ipftest(1), ipf(5)
.SH DIAGNOSTICS
.PP
Needs to be run as root for the packet filtering lists to actually
be affected inside the kernel.
.SH BUGS
.PP
If you find any, please send email to me at darrenr@cyber.com.au