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ng_netflow(4)

NAME

     ng_netflow -- Cisco's NetFlow implementation

SYNOPSIS

     #include <sys/types.h>
     #include <netinet/in.h>
     #include <netgraph/netflow/ng_netflow.h>

DESCRIPTION

     The ng_netflow node implements Cisco's NetFlow export protocol on a
     router running FreeBSD.  The ng_netflow node listens for incoming traffic
     and identifies unique flows in it.  Flows are distinguished by endpoint
     IP addresses, TCP/UDP port numbers, ToS and input interface.  Expired
     flows are exported out of the node in NetFlow version 5 UDP datagrams.
     Expiration reason can be one of the following:

     -	 RST or FIN TCP segment.

     -	 Active timeout.  Flows cannot live more than the specified period of
	 time.	The default is 1800 seconds (30 minutes).

     -	 Inactive timeout.  A flow was inactive for the specified period of
	 time.	The default is 15 seconds.

     Export information is stored in NetFlow version 5 datagrams.

HOOKS

     This node type supports up to NG_NETFLOW_MAXIFACES hooks named iface0,
     iface1, etc., plus a single hook named export.  The node reads data on
     iface* hooks, and sends export datagrams to the export hook.  In normal
     operation, the export hook is connected to the inet/dgram/udp hook of the
     ng_ksocket(4) node.

CONTROL MESSAGES

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

     NGM_NETFLOW_INFO
	     Returns some node statistics and the current timeout values in a
	     struct ng_netflow_info.

     NGM_NETFLOW_IFINFO
	     Returns information about the ifaceN hook.  The hook number is
	     passed as an argument.

     NGM_NETFLOW_SETDLT
	     Sets data link type on the ifaceN hook.  Currently, supported
	     types are raw IP datagrams and Ethernet.  This messsage type uses
	     struct ng_netflow_setdlt as an argument:

		 struct ng_netflow_setdlt {
			 uint16_t iface;	 /* which iface to operate on */
			 uint8_t  dlt;		 /* DLT_XXX from bpf.h */
		 };

	     The requested ifaceN hook must already be connected, otherwise
	     message send operation will return an error.

	     land.  This message requires struct ng_netflow_setifindex as an
	     argument:

		 struct ng_netflow_setifindex {
			 u_int16_t iface;	 /* which iface to operate on */
			 u_int16_t index;	 /* new index */
		 };

	     The requested ifaceN hook must already be connected, otherwise
	     the message send operation will return an error.

     NGM_NETFLOW_SETTIMEOUTS
	     Sets values in seconds for NetFlow active/inactive timeouts.
	     This message requires struct ng_netflow_settimeouts as an argu-
	     ment:

		 struct ng_netflow_settimeouts {
			 uint32_t	 inactive_timeout;
			 uint32_t	 active_timeout;
		 };

     NGM_NETFLOW_SHOW
	     This control message asks a node to dump the entire contents of
	     the flow cache.  It is called from flowctl(8), not directly from
	     ngctl(8).

ASCII CONTROL MESSAGES

     Most binary control messages have an ASCII equivalent.  The supported
     ASCII commands are:

     NGM_NETFLOW_INFO	      "info"
     NGM_NETFLOW_IFINFO       "ifinfo %u"
     NGM_NETFLOW_SETDLT       "setdlt { iface = %u dlt = %u }"
     NGM_NETFLOW_SETIFINDEX   "setifindex { iface = %u index = %u }"
     NGM_NETFLOW_SETTIMEOUTS  "settimeouts { inactive = %u active = %u }"

SHUTDOWN

     This node shuts down upon receipt of a NGM_SHUTDOWN control message, or
     when all hooks have been disconnected.

EXAMPLES

     The simplest possible configuration is one Ethernet interface, where flow
     collecting is enabled.

	   /usr/sbin/ngctl -f- <<-SEQ
		   mkpeer fxp0: tee lower right
		   connect fxp0: fxp0:lower upper left
		   mkpeer fxp0:lower netflow right2left iface0
		   name fxp0:lower.right2left netflow
		   mkpeer netflow: ksocket export inet/dgram/udp
		   msg netflow:export connect inet/10.0.0.1:4444
	   SEQ

     This is a more complicated example of a router with 2 NetFlow-enabled
     interfaces fxp0 and ng0.  Note that the ng0: node in this example is con-
     nected to ng_tee(4).

	   /usr/sbin/ngctl -f- <<-SEQ
		   # Create tee on fxp0, and connect it to iface1 hook
		   mkpeer fxp0: tee lower right
		   connect fxp0: fxp0:lower upper left
		   name fxp0:lower fxp0_tee
		   connect fxp0_tee: netflow: right2left iface1

		   # Create ksocket node on export hook, and configure it
		   # to send exports to proper destination
		   mkpeer netflow: ksocket export inet/dgram/udp
		   msg netflow:export connect inet/10.0.0.1:4444
	   SEQ

SEE ALSO

     flowctl(4), netgraph(4), ng_ksocket(4), ng_tee(4), ngctl(8)

     http://www.cisco.com/warp/public/cc/pd/iosw/ioft/neflct/tech/napps_wp.htm

AUTHORS

     The ng_netflow node type was written by Gleb Smirnoff
     <glebius@FreeBSD.org>, based on ng_ipacct written by Roman V. Palagin
     <romanp@unshadow.net>.

BUGS

     The ng_netflow node type does not fill in AS numbers.  This is due to the
     lack of necessary information in the kernel routing table.  However, this
     information can be injected into the kernel from a routing daemon such as
     GNU Zebra.  This functionality may become available in future releases.

FreeBSD 5.4			 April 8, 2004			   FreeBSD 5.4

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