The NetFlow v9 (Custom) sensor receives traffic data from a NetFlow v9-compatible device and shows the traffic by type. With this sensor, you can define your own channel definitions to divide traffic into different channels.
Make sure that the sensor matches the NetFlow version that your device exports.
NetFlow v9 (Custom) Sensor
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
Sensor in Other Languages
Dutch: NetFlow v9 (aangepast)
French: NetFlow v9 personnalisé
German: NetFlow v9 (Benutzerdefiniert)
Japanese: NetFlow v9(カスタム)
Portuguese: NetFlow v9 (customizado)
Russian: NetFlow v9 (настраиваемый)
Simplified Chinese: NetFlow v9 (自定义)
Spanish: NetFlow v9 (personalizado)
Remarks
This sensor has a very high performance impact. We recommend that you use no more than 50 of this sensor on each probe.
This sensor requires that the NetFlow export of the respective version is enabled on the target system. The target system must send the flow data stream to the IP address of the probe system.
This sensor does not officially support more than 50 channels.
This sensor does not support cluster probes. You can only set it up on local probes or remote probes.
If the name contains angle brackets (<>), PRTG replaces them with braces ({}) for security reasons. For more information, see the Knowledge Base: What security features does PRTG include?
This setting is for your information only. You cannot change it.
Tags
Enter one or more tags. Confirm each tag with the Spacebar key, a comma, or the Enter key. You can use tags to group objects and use tag-filtered views later on. Tags are not case-sensitive. Tags are automatically inherited.
It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).
For performance reasons, it can take some minutes until you can filter for new tags that you added.
The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:
bandwidthsensor
netflowsensor
Priority
Select a priority for the sensor. This setting determines the position of the sensor in lists. The highest priority is at the top of a list. Choose from the lowest priority () to the highest priority ().
NetFlow v9 Specific Settings
NetFlow v9 Specific Settings
Setting
Description
Receive Packets on UDP Port
Enter the User Datagram Protocol (UDP) port number on which the flow packets are received. It must match the UDP port number in the NetFlow export options of the hardware router device. Enter an integer.
When you configure the export, make sure that you select the appropriate NetFlow version for this sensor.
Sender IP Address
Enter the IP address of the sending device that you want to receive the NetFlow from. Enter an IP address to only receive data from a specific device or leave the field empty to receive data from any device on the specified port.
Receive Packets on IP Address
Select the IP addresses on which PRTG listens to NetFlow packets. The list of IP addresses is specific to your setup. To select an IP address, enable a check box in front of the respective line. The IP address that you select must match the IP address in the NetFlow export options of the hardware router device.
When you configure the export, make sure that you select the appropriate NetFlow version for this sensor.
You can also select all items or cancel the selection by using the check box in the table header.
Active Flow Timeout (Minutes)
Enter a time span in minutes after which the sensor must receive new flow data. If the timeout elapses and the sensor receives no new data during this time, it shows the Unknownstatus. Enter an integer. The maximum timeout is 60 minutes.
We recommend that you set the timeout one minute longer than the timeout in the hardware router device.
If you set this value too low, flow information might be lost.
If the target device sends incorrect time information that results in wrong monitoring data, try to use 0 as the active flow timeout. This ignores the start and stop information of a flow as provided by the device and accounts all data to the current point in time. It might result in spikes but all data is captured.
Sampling Mode
Define if you want to use the sampling mode:
Off: Use the standard flow.
On: Use the sampling mode and specify the Sampling Rate below.
This setting must match the setting in the xFlow exporter.
Sampling Rate
This setting is only visible if you select On above.
Enter a number that matches the sampling rate in your device that exports the flows. If the number is different, monitoring results will be incorrect. Enter an integer.
Channel Definition
Enter a channel definition to divide the traffic into different channels. Enter each definition in one line. The sensor accounts all traffic that you do not define a channel for to the default channel Other.
Extensive use of many filters can cause load problems on the probe system. We recommend that you define specific, well-chosen filters for the data that you really want to analyze. We recommend that you do not use more than 20 channels in graphs and tables, and not more than 100 channels in total. For performance reasons, we recommend that you add several sensors with fewer channels each.
Stream Data Handling
Define what PRTG does with the stream and packet data:
Discard stream data (recommended): Do not store the stream and packet data.
Store stream data only for the 'Other' channel: Only store stream and packet data that is not otherwise filtered and is therefore accounted to the default Other channel. PRTG stores this data in the \StreamLog subfolder of the PRTG data directory on the probe system. The file name is Streams Sensor [ID] (1).csv. This setting is for debugging purposes. PRTG overwrites this file with each scanning interval.
Store all stream data: Store all stream and packet data. This setting is for debugging purposes. PRTG overwrites this file with each scanning interval.
Use with caution. It can create huge data files. We recommend that you only use this setting for a short time.
Filtering
For detailed information, see section Filter Rules.
Filtering
Setting
Description
Include Filter
Define if you want to filter any traffic. If you leave this field empty, the sensor includes all traffic. To include specific traffic only, define filters using a special syntax.
Exclude Filter
First, the sensor considers the filters in Include Filter. From this subset, you can explicitly exclude traffic, using the same syntax.
Sensor Display
Sensor Display
Setting
Description
Primary Channel
Select a channel from the list to define it as the primary channel. In the device tree, the last value of the primary channel is always displayed below the sensor's name. The available options depend on what channels are available for this sensor.
You can set a different primary channel later by clicking below a channel gauge on the sensor's Overview tab.
Graph Type
Define how different channels are shown for this sensor:
Show channels independently (default): Show a graph for each channel.
Stack channels on top of each other: Stack channels on top of each other to create a multi-channel graph. This generates a graph that visualizes the different components of your total traffic. You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings).
Stack Unit
This setting is only visible if you select Stack channels on top of each other above.
Select a unit from the list. All channels with this unit are stacked on top of each other. By default, you cannot exclude single channels from stacking if they use the selected unit. However, there is an advanced procedure to do so.
Primary Toplist
Primary Toplist
Setting
Description
Primary Toplist
Define which Toplist is the primary Toplist of the sensor:
Top Talkers
Top Connections
Top Protocols
[Any custom Toplists you add]
PRTG shows the primary Toplist in maps when you add a Toplist object.
Inherited Settings
By default, all of these settings are inherited from objects that are higher in the hierarchy. We recommend that you change them centrally in the root group settings if necessary. To change a setting for this object only, click under the corresponding setting name to disable the inheritance and to display its options.
For more information, see section Root Group Settings, section Scanning Interval.
Schedules, Dependencies, and Maintenance Window
You cannot interrupt the inheritance for schedules, dependencies, and maintenance windows. The corresponding settings from the parent objects are always active. However, you can define additional schedules, dependencies, and maintenance windows. They are active at the same time as the parent objects' settings.
Schedules, Dependencies, and Maintenance Window
For more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.
Access Rights
Access Rights
For more information, see section Root Group Settings, section Access Rights.
Channel Unit Configuration
Channel Unit Configuration
For more information, see section Root Group Settings, section Channel Unit Configuration.
Toplists
For all Flow (NetFlow, jFlow, sFlow, IPFIX) and Packet Sniffer sensors, Toplists are available on the sensor's Overview tab. Using Toplists, you can review traffic data for small time periods in great detail.
Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Internet Control Message Protocol (ICMP), Open Shortest Path First (OSPF), any number
ToS
Type of Service (ToS): any number
DSCP
Differentiated Services Code Point (DSCP): any number
The following filter rules apply to NetFlow v9 sensors only.
Field
Possible Filter Values
Interface
Any number
ASI
Any number
InboundInterface
Any number
OutboundInterface
Any number
SenderIP
IP address of the sending device. Use this if you have several devices that send flow data on the same port, and you want to divide the traffic of each device into a different channel.
Possible values: IP address or DNS name
SourceASI
Any number
DestinationASI
Any number
MAC
Physical address
SourceMAC
Physical address
DestinationMAC
Physical address
Mask
Mask values represent subnet masks in the form of a single number (number of contiguous bits).
DestinationMask
Mask values represent subnet masks in the form of a single number (number of contiguous bits).
NextHop
IP address or DNS name
VLAN
VLAN values represent a VLAN identifier (any number).
SourceVLAN
VLAN values represent a VLAN identifier (any number).
DestinationVLAN
VLAN values represent a VLAN identifier (any number).
Channel List
Which channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.
Channel
Description
[Custom]
The traffic by type according to the channel definition
Downtime
In the channel table on the Overview tab, this channel never shows any values. PRTG uses this channel in graphs and reports to show the amount of time in which the sensor was in the Down status