freebsd-skq/share/man/man4/ipfirewall.4

.\"
.\" $FreeBSD$
.\"
.Dd October 25, 2012
.Dt IPFW 4
.Os
.Sh NAME
.Nm ipfw
.Nd IP packet filter and traffic accounting
.Sh SYNOPSIS
To compile
the driver
into the kernel, place the following option in the kernel configuration
file:
.Bd -ragged -offset indent
.Cd "options IPFIREWALL"
.Ed
.Pp
Other related kernel options
which may also be useful are:
.Bd -ragged -offset indent
.Cd "options IPFIREWALL_DEFAULT_TO_ACCEPT"
.Cd "options IPFIREWALL_VERBOSE"
.Cd "options IPFIREWALL_VERBOSE_LIMIT=100"
.Ed
.Pp
To load
the driver
as a module at boot time, add the following line into the
.Xr loader.conf 5
file:
.Bd -literal -offset indent
ipfw_load="YES"
.Ed
.Sh DESCRIPTION
The
.Nm
system facility allows filtering,
redirecting, and other operations on
.Tn IP
packets travelling through
network interfaces.
.Pp
The default behavior of
.Nm
is to block all incoming and outgoing traffic.
This behavior can be modified, to allow all traffic through the
.Nm
firewall by default, by enabling the
.Dv IPFIREWALL_DEFAULT_TO_ACCEPT
kernel option.
This option may be useful when configuring
.Nm
for the first time.
If the default
.Nm
behavior is to allow everything, it is easier to cope with
firewall-tuning mistakes which may accidentally block all traffic.
.Pp
To enable logging of packets passing through
.Nm ,
enable the
.Dv IPFIREWALL_VERBOSE
kernel option.
The
.Dv IPFIREWALL_VERBOSE_LIMIT
option will prevent
.Xr syslogd 8
from flooding system logs or causing local Denial of Service.
This option may be set to the number of packets which will be logged on
a per-entry basis before the entry is rate-limited.
.Pp
The user interface for
.Nm
is implemented by the
.Xr ipfw 8
utility, so please refer to the
.Xr ipfw 8
manpage for a complete description of the
.Nm
capabilities and how to use it.
.Sh SEE ALSO
.Xr setsockopt 2 ,
.Xr divert 4 ,
.Xr ip 4 ,
.Xr ipfw 8 ,
.Xr sysctl 8 ,
.Xr syslogd 8 ,
.Xr pfil 9
add missing cvs Id lines. 1997-03-07 02:50:01 +00:00			`.\"`
$Id$ -> $FreeBSD$ 1999-08-28 00:22:10 +00:00			`.\" $FreeBSD$`
add missing cvs Id lines. 1997-03-07 02:50:01 +00:00			`.\"`
Remove the IPFIREWALL_FORWARD kernel option and make possible to turn on the related functionality in the runtime via the sysctl variable net.pfil.forward. It is turned off by default. Sponsored by: Yandex LLC Discussed with: net@ MFC after: 2 weeks 2012-10-25 09:39:14 +00:00			`.Dd October 25, 2012`
Remove stale information from these two manpage, and point the readers to the one up-to-date page which is ipfw(8). MFC after: 3 days 2002-10-28 07:24:58 +00:00			`.Dt IPFW 4`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Os`
			`.Sh NAME`
Remove stale information from these two manpage, and point the readers to the one up-to-date page which is ipfw(8). MFC after: 3 days 2002-10-28 07:24:58 +00:00			`.Nm ipfw`
Make this file bare a small resemblance to reality again Requested from: Archie Cobbs (archie@whistle.com) 1997-06-23 02:12:21 +00:00			`.Nd IP packet filter and traffic accounting`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`.Sh SYNOPSIS`
			`To compile`
mdoc: Avoid playing tricks with Ns: If Nm is present in the SYNOPSIS section, it will be output on its own line. Ns cancels this effect however. This change is also consistent with the rest of our manual pages. 2012-05-14 16:25:17 +00:00			`the driver`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`into the kernel, place the following option in the kernel configuration`
			`file:`
			`.Bd -ragged -offset indent`
			`.Cd "options IPFIREWALL"`
			`.Ed`
			`.Pp`
mdoc: Avoid playing tricks with Ns: If Nm is present in the SYNOPSIS section, it will be output on its own line. Ns cancels this effect however. This change is also consistent with the rest of our manual pages. 2012-05-14 16:25:17 +00:00			`Other related kernel options`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`which may also be useful are:`
			`.Bd -ragged -offset indent`
			`.Cd "options IPFIREWALL_DEFAULT_TO_ACCEPT"`
			`.Cd "options IPFIREWALL_VERBOSE"`
			`.Cd "options IPFIREWALL_VERBOSE_LIMIT=100"`
			`.Ed`
			`.Pp`
			`To load`
mdoc: Avoid playing tricks with Ns: If Nm is present in the SYNOPSIS section, it will be output on its own line. Ns cancels this effect however. This change is also consistent with the rest of our manual pages. 2012-05-14 16:25:17 +00:00			`the driver`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`as a module at boot time, add the following line into the`
Use the loader.conf example. Approved by: trhodes (mentor), keramida (mentor) MFC after: 3 days 2006-10-16 07:56:36 +00:00			`.Xr loader.conf 5`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`file:`
			`.Bd -literal -offset indent`
Use the loader.conf example. Approved by: trhodes (mentor), keramida (mentor) MFC after: 3 days 2006-10-16 07:56:36 +00:00			`ipfw_load="YES"`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`.Ed`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh DESCRIPTION`
mdoc(7) police: scheduled sweep. Approved by: re 2002-11-29 11:39:20 +00:00			`The`
			`.Nm`
			`system facility allows filtering,`
			`redirecting, and other operations on`
			`.Tn IP`
			`packets travelling through`
			`network interfaces.`
A QUICK pass through this man page to make it conform to mdoc standards and to clean up some of the English. The job is nowhere complete. This man page would be a good project for someone who knows something about the firewall software, and would like to contribute to the documentation effort. Many of the things in this man page are out of date and do not reflect reality. 1996-07-11 02:37:59 +00:00			`.Pp`
- Move available kernel options to SYNOPSIS, describe how to enable ipfw from within rc.conf. - Remove IPDIVERT kernel option - Add notes about IPFIREWALL_DEFAULT_TO_ACCEPT and IPFIREWALL_FORWARD Reviewed by: ru Approved by: keramida (mentor), trhodes (mentor) MFC after: 1 week 2006-09-01 08:50:05 +00:00			`The default behavior of`
			`.Nm`
			`is to block all incoming and outgoing traffic.`
			`This behavior can be modified, to allow all traffic through the`
			`.Nm`
			`firewall by default, by enabling the`
			`.Dv IPFIREWALL_DEFAULT_TO_ACCEPT`
			`kernel option.`
			`This option may be useful when configuring`
			`.Nm`
			`for the first time.`
			`If the default`
			`.Nm`
			`behavior is to allow everything, it is easier to cope with`
			`firewall-tuning mistakes which may accidentally block all traffic.`
			`.Pp`
			`To enable logging of packets passing through`
			`.Nm ,`
			`enable the`
			`.Dv IPFIREWALL_VERBOSE`
			`kernel option.`
			`The`
			`.Dv IPFIREWALL_VERBOSE_LIMIT`
			`option will prevent`
			`.Xr syslogd 8`
			`from flooding system logs or causing local Denial of Service.`
			`This option may be set to the number of packets which will be logged on`
			`a per-entry basis before the entry is rate-limited.`
			`.Pp`
Remove stale information from these two manpage, and point the readers to the one up-to-date page which is ipfw(8). MFC after: 3 days 2002-10-28 07:24:58 +00:00			`The user interface for`
mdoc(7) police: scheduled sweep. Approved by: re 2002-11-29 11:39:20 +00:00			`.Nm`
Remove stale information from these two manpage, and point the readers to the one up-to-date page which is ipfw(8). MFC after: 3 days 2002-10-28 07:24:58 +00:00			`is implemented by the`
			`.Xr ipfw 8`
mdoc(7) police: scheduled sweep. Approved by: re 2002-11-29 11:39:20 +00:00			`utility, so please refer to the`
			`.Xr ipfw 8`
			`manpage for a complete description of the`
			`.Nm`
			`capabilities and how to use it.`
Move ipfirewall.4 & snp.4 facility manpage to share/man/man4 1995-02-17 18:48:36 +00:00			`.Sh SEE ALSO`
A QUICK pass through this man page to make it conform to mdoc standards and to clean up some of the English. The job is nowhere complete. This man page would be a good project for someone who knows something about the firewall software, and would like to contribute to the documentation effort. Many of the things in this man page are out of date and do not reflect reality. 1996-07-11 02:37:59 +00:00			`.Xr setsockopt 2 ,`
Make this file bare a small resemblance to reality again Requested from: Archie Cobbs (archie@whistle.com) 1997-06-23 02:12:21 +00:00			`.Xr divert 4 ,`
Sort cross refereces in section SEE ALSO. 1997-09-29 10:11:02 +00:00			`.Xr ip 4 ,`
Make this file bare a small resemblance to reality again Requested from: Archie Cobbs (archie@whistle.com) 1997-06-23 02:12:21 +00:00			`.Xr ipfw 8 ,`
Document that the IPFW messages are logged via syslogd(8). 2001-02-22 09:12:44 +00:00			`.Xr sysctl 8 ,`
Note that IPFIREWALL depends on PFIL_HOOKS compiled into the kernel as well. Submitted by: ceri, simon (mdoc fixes) 2004-08-19 18:04:10 +00:00			`.Xr syslogd 8 ,`
			`.Xr pfil 9`