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NG_NAT(4)	       FreeBSD Kernel Interfaces Manual		     NG_NAT(4)

NAME
     ng_nat -- NAT netgraph node type

SYNOPSIS
     #include <netgraph/ng_nat.h>

DESCRIPTION
     An	ng_nat node performs network address translation (NAT) of packets
     passing through it.  A nat	node uses libalias(3) engine for packet	alias-
     ing.  At this moment it supports only the basic functionality of the
     library.

HOOKS
     This node type has	two hooks:

     out     Packets received on this hook are considered outgoing and will be
	     masqueraded to a configured address.

     in	     Packets coming on this hook are considered	incoming and will be
	     dealiased.

CONTROL	MESSAGES
     This node type supports the generic control messages, plus	the following:

     NGM_NAT_SET_IPADDR	(setaliasaddr)
	     Configure aliasing	address	for a node.  After both	hooks have
	     been connected and	aliasing address was configured, a node	is
	     ready for aliasing	operation.

SHUTDOWN
     This node shuts down upon receipt of a NGM_SHUTDOWN control message, or
     when both hooks are disconnected.

EXAMPLES
     In	the following example, the packets are injected	into a nat node	using
     the ng_ipfw(4) node.

	   # Create NAT	node
	   ngctl mkpeer	ipfw: nat 60 out
	   ngctl name ipfw:60 nat
	   ngctl connect ipfw: nat: 61 in
	   ngctl msg nat: setaliasaddr x.y.35.8

	   # Divert traffic into NAT node
	   ipfw	add 300	netgraph 61 all	from any to any	in via fxp0
	   ipfw	add 400	netgraph 60 all	from any to any	out via	fxp0

	   # Let packets continue with after being (de)aliased
	   sysctl net.inet.ip.fw.one_pass=0

     The ng_nat	node can be inserted right after the ng_iface(4) node in the
     graph.  In	the following example, we perform masquerading on a serial
     line with HDLC encapsulation.

	   /usr/sbin/ngctl -f- <<-SEQ
		   mkpeer cp0: cisco rawdata downstream
		   name	cp0:rawdata hdlc
		   mkpeer hdlc:	nat inet in
		   name	hdlc:inet nat
		   mkpeer nat: iface out inet
		   msg nat: setaliasaddr x.y.8.35
	   SEQ
	   ifconfig ng0	x.y.8.35 x.y.8.1

SEE ALSO
     libalias(3), ng_ipfw(4), natd(8), ngctl(8)

HISTORY
     The ng_nat	node type was implemented in FreeBSD 6.0.

AUTHORS
     Gleb Smirnoff <glebius@FreeBSD.org>

FreeBSD	6.0			  May 6, 2005			   FreeBSD 6.0

NAME | SYNOPSIS | DESCRIPTION | HOOKS | CONTROL MESSAGES | SHUTDOWN | EXAMPLES | SEE ALSO | HISTORY | AUTHORS

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