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IPFW(4)		       FreeBSD Kernel Interfaces Manual		       IPFW(4)

NAME
     ipfw -- IP	packet filter and traffic accounting

SYNOPSIS
     To	compile	ipfw into the kernel, place the	following option in the	kernel
     configuration file:

	   options IPFIREWALL

     Other kernel options related to ipfw which	may also be useful are:

	   options IPFIREWALL_DEFAULT_TO_ACCEPT
	   options IPFIREWALL_FORWARD
	   options IPFIREWALL_VERBOSE
	   options IPFIREWALL_VERBOSE_LIMIT=100

     To	load ipfw as a module at boot time, add	the following line into	the
     loader.conf(5) file:

	   ipfw_load="YES"

DESCRIPTION
     The ipfw system facility allows filtering,	redirecting, and other opera-
     tions on IP packets travelling through network interfaces.

     The default behavior of ipfw is to	block all incoming and outgoing	traf-
     fic.  This	behavior can be	modified, to allow all traffic through the
     ipfw firewall by default, by enabling the IPFIREWALL_DEFAULT_TO_ACCEPT
     kernel option.  This option may be	useful when configuring	ipfw for the
     first time.  If the default ipfw behavior is to allow everything, it is
     easier to cope with firewall-tuning mistakes which	may accidentally block
     all traffic.

     To	enable logging of packets passing through ipfw,	enable the
     IPFIREWALL_VERBOSE	kernel option.	The IPFIREWALL_VERBOSE_LIMIT option
     will prevent 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.

     Policy routing and	transparent forwarding features	of ipfw	can be enabled
     by	IPFIREWALL_FORWARD kernel option.

     The user interface	for ipfw is implemented	by the ipfw(8) utility,	so
     please refer to the ipfw(8) manpage for a complete	description of the
     ipfw capabilities and how to use it.

SEE ALSO
     setsockopt(2), divert(4), ip(4), ipfw(8), sysctl(8), syslogd(8), pfil(9)

FreeBSD	10.1		       September 1, 2006		  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | SEE ALSO

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