PRTG Manual: jFlow v5 (Custom) Sensor

Sensor Name

Enter a meaningful name to identify the sensor. By default, PRTG shows this name in the device tree, as well as in alarms, logs, notifications, reports, maps, libraries, and tickets.

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe. This setting is shown for your information only and cannot be changed here.

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 (<>).

The sensor has the following default tags that are automatically predefined in the sensor's settings when you add the sensor:

• bandwidthsensor
• jflowsensor

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 ().

Receive jFlow Packets on UDP Port

Enter the User Datagram Protocol (UDP) port number on which PRTG receives the flow packets. It must match the one you have configured in the jFlow export options of your hardware router device. Enter an integer value.

When you configure the export, make sure that you select the appropriate jFlow version for this sensor.

Sender IP

Enter the IP address of the sending device that you want to receive the jFlow from. Enter an IP address to receive data from a specific device only, or leave the field empty to receive data from any device on the specified port.

Receive jFlow Packets on IP

Select the IP address(es) on which PRTG listens to jFlow packets. The list of IP addresses you see here is specific to your setup. To select an IP address, add a check mark in front of the respective line. You can also select all items or cancel the selection by using the check box in the table header. The IP address that you select here must match the IP address that you configured in the jFlow export options of your hardware router device.

When you configure the export, make sure that you select the appropriate jFlow version for this sensor.

Active Flow Timeout (Minutes)

Enter a time span in minutes after which new flow data must be received. If the timeout is reached and no new data was received during this time, the sensor changes to an Unknown status. Enter an integer value.

We recommend that you set the timeout one minute longer than the respective timeout configured in your hardware router device. The maximum timeout is 60 minutes.

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?

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 when sampling mode is On above. Enter a number that matches the sampling rate in your device that exports the xFlows. If the number is different, monitoring results will be incorrect. Enter an integer value.

Channel Definition

Enter a channel definition to divide the traffic into different channels. Write each definition in one line. All traffic for which no channel is defined is accounted to the default channel named Other.

For detailed information, see section Channel Definitions for xFlow, IPFIX, and Packet Sniffer Sensors.

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 you really want to analyze.

Log Stream Data to Disk (for Debugging)

Define if you want the probe to write a logfile of the stream and packet data to the \StreamLog subfolder of the PRTG data directory:

• None (recommended): Do not write additional logfiles. We recommended that you select this for normal use cases.
• Only for the 'Other' channel: Only write logfiles of data that is not otherwise filtered and therefore accounted to the default Other channel.
• All stream data: Write logfiles for all data received.

Use with caution. When enabled, huge data files can be created. We recommend that you use this for a short time and for debugging purposes only.

Include Filter

Define if you want to filter any traffic. If you leave this field empty, all traffic is included. To include specific traffic only, define filters using a special syntax.

Exclude Filter

First, the filters defined in the Include Filter field are considered. From this subset, you can explicitly exclude traffic, using the same syntax.

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 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.

Primary Toplist

Define which Toplist is your primary Toplist:

• Top Talkers
• Top Connections
• Top Protocols
• [Any custom Toplists you have added]

The primary Toplist is shown in maps when adding a Toplist object.

Scanning Interval

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
• 1 day

You can change the available intervals in the system administration on PRTG on premises installations.

If a Sensor Query Fails

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.

Schedule

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.

Maintenance Window

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:

• Not set (monitor continuously): 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 a 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.

Maintenance Begins

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.

Maintenance Ends

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.

Dependency Type

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.

Dependency

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.

Dependency Delay (Sec.)

This setting is only visible if you enable 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.

User Group Access

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.

Channel Unit Types

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, these settings can be inherited 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.

IP

IP address or Domain Name System (DNS) name

Port

Any number

SourceIP

IP address or Domain Name System (DNS) name

SourcePort

Any number

DestinationIP

IP address or Domain Name System (DNS) name

DestinationPort

Any number

Protocol

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

Interface

Any number

ASI

Any number

InboundInterface

Any number

OutboundInterface

Any number

SenderIP

IP 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