<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: NetFlow v9 Sensor
The NetFlow v9 sensor receives traffic data from a NetFlow v9-compatible device and shows the traffic by type. This sensor has several filter options to divide traffic into different channels.
Make sure that the sensor matches the NetFlow version that your device exports.
NetFlow v9 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
- French: NetFlow v9
- German: NetFlow v9
- Japanese: NetFlow v9
- Portuguese: NetFlow v9
- Russian: NetFlow v9
- Simplified Chinese: NetFlow v9
- Spanish: NetFlow v9
Remarks
You cannot add this sensor to the hosted probe of a PRTG Hosted Monitor instance. If you want to use this sensor, add it to a remote probe device.
Add Sensor
The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the settings that are required to create the sensor. You can change nearly all settings on the sensor's Settings tab after creation.
Basic Sensor Settings
Click the Settings tab of a sensor to change its settings.
Basic Sensor Settings
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Sensor Name
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Enter a name to identify the sensor.
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Parent Tags
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Shows tags that the sensor inherits from its parent device, parent group, and parent probe.
This setting is for your information only. You cannot change it.
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Tags
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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
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Priority
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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 ().
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NetFlow v9 Specific Settings
NetFlow v9 Specific Settings
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Receive Packets on UDP Port
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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 value.
When you configure the export, make sure that you select the appropriate NetFlow version for this sensor.
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Sender IP Address
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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.
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Receive Packets on IP Address
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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.
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Active Flow Timeout (Minutes)
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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 Unknown status. Enter an integer value. 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.
For more details, see the Knowledge Base: What is the Active Flow Timeout in flow sensors?
If the target device sends incorrect time information that results in wrong monitoring data, try to use 0 as 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.
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Sampling Mode
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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.
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Sampling Rate
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This setting is only visible if you select On above. Enter a number that matches the sampling rate in the exporting device. If the number is different, monitoring results will be incorrect. Enter an integer value.
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Stream Data Handling
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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. If you enable this setting, it can create huge data files. We recommend that you only use this setting for a short time.
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Channel Configuration
Channel Configuration
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Channel Selection
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Define the categories that the sensor accounts the traffic to:
- Web: Internet web traffic.
- File Transfer: Traffic from FTP.
- Mail: Internet mail traffic.
- Chat: Traffic from chat and instant messaging.
- Remote Control: Traffic from remote control applications such as RDP, SSH, Telnet, and VNC.
- Infrastructure: Traffic from network services such as DHCP, DNS, Ident, ICMP, and SNMP.
- NetBIOS: Traffic from NetBIOS communication.
- Citrix: Traffic from Citrix applications.
- Other Protocols: Traffic from various other protocols via UDP and TCP.
For each group, you can select how many channels the sensor uses, that is, how detailed the sensor divides the traffic. For each group, choose from:
- No (): Do not account traffic of this group in its own channel. The sensor accounts all traffic of this group to the default channel named Other.
- Yes (): Count all traffic of this group and summarize it in one channel.
- Detail (): Count all traffic of this group and further divide it into different channels. The traffic appears in several channels that you can see in the Content column.
Extensive use of this option can cause load problems on the probe system. We recommend that you set specific, well-chosen filters for the data that you really want to analyze.
You can change the default configuration for groups and channels. For details, see the Knowledge Base: How can I change the default groups and channels for flow and Packet Sniffer sensors?
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Filtering
For detailed information, see section Filter Rules.
Filtering
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Include Filter
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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.
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Exclude Filter
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First, the sensor considers the filters in Include Filter. From this subset, you can explicitly exclude traffic, using the same syntax.
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Sensor Display
Sensor Display
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Primary Channel
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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.
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Graph Type
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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).
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Stack Unit
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This setting is only visible if you enable Stack channels on top of each other as Graph Type. 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.
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Primary Toplist
Primary Toplist
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Primary Toplist
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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.
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Inherited Settings
By default, all of the following 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 Inheritance of Settings.
Scanning Interval
Click to interrupt the inheritance.
Scanning Interval
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Scanning Interval
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Select a scanning interval from the dropdown list. The scanning interval determines the amount of time that the sensor waits between two scans. Choose from:
- 30 seconds
- 60 seconds
- 5 minutes
- 10 minutes
- 15 minutes
- 30 minutes
- 1 hour
- 4 hours
- 6 hours
- 12 hours
- 24 hours
You can change the available intervals in the system administration of PRTG Network Monitor.
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If a Sensor Query Fails
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Select the number of scanning intervals that the sensor has time to reach and to check a device again if a sensor query fails. Depending on the option that you select, the sensor can try to reach and to check a device again several times before the sensor shows the Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows the Warning status. Choose from:
- Set sensor to down immediately: Set the sensor to the Down status immediately after the first request fails.
- Set sensor to warning for 1 interval, then set to down (recommended): Set the sensor to the Warning status after the first request fails. If the second request also fails, the sensor shows the Down status.
- Set sensor to warning for 2 intervals, then set to down: Set the sensor to the Down status only after the third request fails.
- Set sensor to warning for 3 intervals, then set to down: Set the sensor to the Down status only after the fourth request fails.
- Set sensor to warning for 4 intervals, then set to down: Set the sensor to the Down status only after the fifth request fails.
- Set sensor to warning for 5 intervals, then set to down: Set the sensor to the Down status only after the sixth request fails.
Sensors that monitor via Windows Management Instrumentation (WMI) always wait at least one scanning interval before they show the Down status. It is not possible to immediately set a WMI sensor to the Down status, so the first option does not apply to these sensors. All other options can apply.
If you define error limits for a sensor's channels, the sensor immediately shows the Down status. None of the interval options apply.
If a channel uses lookup values, the sensor immediately shows the Down status. None of the interval options apply.
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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
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Schedule
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Select a schedule from the list. You can use schedules to monitor during a certain time span (days or hours) every week. Choose from:
- None
- Saturdays
- Sundays
- Weekdays
- Weekdays Eight-To-Eight (08:00 - 20:00)
- Weekdays Nights (17:00 - 09:00)
- Weekdays Nights (20:00 - 08:00)
- Weekdays Nine-To-Five (09:00 - 17:00)
- Weekends
You can create schedules, edit schedules, or pause monitoring for a specific time span. For more information, see section Schedules.
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Maintenance Window
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Select if you want to set up a one-time maintenance window. During a maintenance window, monitoring stops for the selected object and all child objects. They show the Paused status instead. Choose between:
- Do not set up a one-time maintenance window: Do not set up a one-time maintenance window. Monitoring is always active.
- Set up a one-time maintenance window: Set up a one-time maintenance window and pause monitoring. You can define a time span for the pause below.
To terminate an active maintenance window before the defined end date, change the time entry in Maintenance Ends to a date in the past.
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Maintenance Begins
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This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the one-time maintenance window.
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Maintenance Ends
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This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the one-time maintenance window.
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Dependency Type
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Select a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:
- Use parent: Use the dependency type of the parent object.
- Select a sensor: Use the dependency type of the parent object. Additionally, pause the current object if a specific sensor is in the Down status or in the Paused status because of another dependency.
- Master sensor for parent: Make this sensor the master object for its parent device. The sensor influences the behavior of its parent device: If the sensor is in the Down status, the device is paused. For example, it is a good idea to make a Ping sensor the master object for its parent device to pause monitoring for all other sensors on the device in case the device cannot even be pinged. Additionally, the sensor is paused if the parent group is paused by another dependency.
To test your dependencies, select Simulate Error Status from the context menu of an object that other objects depend on. A few seconds later, all dependent objects are paused. You can check all dependencies under Devices | Dependencies in the main menu bar.
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Dependency
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This setting is only visible if you enable Select a sensor above. Click and use the object selector to select a sensor on which the current object will depend.
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Dependency Delay (Sec.)
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This setting is only visible if you select Select a sensor above. Define a time span in seconds for the dependency delay.
After the master sensor for this dependency returns to the Up status, PRTG additionally delays the monitoring of the dependent objects by the time span you define. This can prevent false alarms, for example, after a server restart or to give systems more time for all services to start. Enter an integer value.
This setting is not available if you set this sensor to Use parent or to be the Master sensor for parent. In this case, define delays in the parent device settings or in its parent group settings.
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Access Rights
Click to interrupt the inheritance.
Access Rights
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User Group Access
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Define the user groups that have access to the sensor. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:
- Inherited: Inherit the access rights settings of the parent object.
- No access: Users in this user group cannot see or edit the sensor. The sensor neither shows up in lists nor in the device tree.
- Read access: Users in this group can see the sensor and view its monitoring results. They cannot edit any settings.
- Write access: Users in this group can see the sensor, view its monitoring results, and edit its settings. They cannot edit its access rights settings.
- Full access: Users in this group can see the sensor, view its monitoring results, edit its settings, and edit its access rights settings.
For more details on access rights, see section Access Rights Management.
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Channel Unit Configuration
Click to interrupt the inheritance.
Channel Unit Configuration
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Channel Unit Types
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For each type of channel, select the unit in which PRTG displays the data. If you define this setting on probe, group, or device level, you can inherit these settings to all sensors underneath. You can set units for the following channel types (if available):
- Bandwidth
- Memory
- Disk
- File
- Custom
Custom channel types are only available on sensor level.
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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.
For more information, see section Toplists.
Filter Rules
The following filter rules apply to all Flow (NetFlow, jFlow, sFlow, IPFIX) and Packet Sniffer sensors.
For more information, see section Filter Rules for Flow, IPFIX, and Packet Sniffer Sensors.
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IP
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IP address or DNS name
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Port
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Any number
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SourceIP
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IP address or DNS name
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SourcePort
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Any number
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DestinationIP
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IP address or DNS name
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DestinationPort
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Any number
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Protocol
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Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Internet Control Message Protocol (ICMP), Open Shortest Path First (OSPF), any number
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ToS
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Type of Service (ToS): any number
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DSCP
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Differentiated Services Code Point (DSCP): any number
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The following filter rules apply to NetFlow v9 sensors only.
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Interface
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Any number
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ASI
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Any number
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InboundInterface
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Any number
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OutboundInterface
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Any number
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SenderIP
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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
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SourceASI
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Any number
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DestinationASI
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Any number
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MAC
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Physical address
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SourceMAC
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Physical address
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DestinationMAC
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Physical address
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Mask
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Mask values represent subnet masks in the form of a single number (number of contiguous bits).
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DestinationMask
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Mask values represent subnet masks in the form of a single number (number of contiguous bits).
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NextHop
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IP address or DNS name
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VLAN
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VLAN values represent a VLAN identifier (any number).
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SourceVLAN
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VLAN values represent a VLAN identifier (any number).
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DestinationVLAN
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VLAN values represent a VLAN identifier (any number).
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Channel List
Which channels the sensor actually shows might depend on the monitored device, the available components, and the sensor setup.
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Chat
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The traffic from chat and instant messaging (Internet Relay Chat (IRC), AOL Instant Messenger (AIM)) in bytes per second
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Citrix
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The traffic from Citrix applications in bytes per second
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Downtime
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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 in percent.
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FTP/P2P
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The traffic from file transfer (File Transfer Protocol (FTP)/Peer-to-Peer (P2P)) in bytes per second
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Infrastructure
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The traffic from network services (Dynamic Host Configuration Protocol (DHCP), Domain Name System (DNS), Ident, Internet Control Message Protocol (ICMP), Simple Network Management Protocol (SNMP)) in bytes per second
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Mail
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The internet mail traffic (Internet Message Access Protocol (IMAP), Post Office Protocol version 3 (POP3), Simple Mail Transfer Protocol (SMTP)) in bytes per second
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NetBIOS
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The traffic from NetBIOS communication in bytes per second
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Other
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The traffic from various other protocols (User Datagram Protocol (UDP), Transmission Control Protocol (TCP)) in bytes per second
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Remote Control
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The traffic from remote control applications (Remote Desktop Protocol (RDP), Secure Shell (SSH), Telnet, Virtual Network Computing (VNC)) in bytes per second
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Total
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The total traffic in bytes per second
This channel is the primary channel by default.
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Various
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The traffic from various other sources in bytes per second
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WWW
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The traffic from the web (HTTP, HTTPS) in bytes per second
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More
Knowledge Base
What is the Active Flow Timeout in flow sensors?
How can I change the default groups and channels for flow and Packet Sniffer sensors?
What security features does PRTG include?
Where is the volume line in graphs?
PAESSLER TOOLS
NetFlow Tester
Sensor Settings Overview
For more information about sensor settings, see the following sections: