<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: Packet Sniffer (Custom) Sensor

The Packet Sniffer (Custom) sensor monitors the headers of data packets that pass a local network card using a built-in packet sniffer. With this sensor, you can define your own channel definitions to divide traffic into different channels.

i_round_blueThis sensor analyzes only header traffic.

i_round_blueThis sensor does not have any predefined channels.

Packet Sniffer (Custom) Sensor

Packet Sniffer (Custom) Sensor

i_square_cyanFor a detailed list and descriptions of the channels that this sensor can show, see section Channel List.

Sensor in Other Languages

  • Dutch: Packet Sniffer (Aangepast)
  • French: Reniflage de paquets personnalisé
  • German: Packet Sniffer (Benutzerdef.)
  • Japanese: パケットスニファー(カスタム)
  • Portuguese: Sniffer de pacotes (customizado)
  • Russian: Анализатор пакетов (нестандартный)
  • Simplified Chinese: 数据包嗅探程序 (自定义)
  • Spanish: Analizador de paquetes (personalizado)


Consider the following remarks and requirements for this sensor:



Performance impact

  • This sensor has a very high performance impact. We recommend that you use no more than 50 of this sensor on each probe.

Probe device

  • By default, this sensor works only on a probe device.


  • This sensor does not officially support more than 50 channels.


  • This sensor supports IPv6.


i_round_blueBy default, you can only monitor traffic passing the probe system where the probe device with the sensor is set up. To monitor other traffic in your network, you can configure a monitoring port (if available) that the switch sends a copy of all traffic to. You can then physically connect this port to a network card of the probe system (either local probe or remote probe system). This way, PRTG can analyze the complete traffic that passes through the switch. This feature of your hardware might be called Switched Port Analyzer (SPAN), port mirroring, or port monitoring.

Hosted probe

i_podYou 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.

Known Issues

  • The sensor does not support the Simulate Error Status option in the Sensor Context Menu. If you trigger this action, the sensor does not show a simulated Down status.

Basic Sensor Settings

Basic Sensor Settings

Basic Sensor Settings

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

  • bandwidthsensor
  • sniffersensor

i_square_cyanFor more information about basic sensor settings, see section Sensor Settings.

Sniffer Specific

i_square_cyanFor more information on filters, see section Filter Rules.

Sniffer Specific

Sniffer Specific



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.

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.

i_square_cyanFor more information, see section Channel Definitions for Flow, IPFIX, and Packet Sniffer Sensors.

i_round_redExtensive 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.

Network Adapters

Select the network adapters that this sensor monitors. You see a list of all adapters that are available on the probe system. To select an adapter, enable the check box in front of the respective name.

i_round_blueYou can also select all items or cancel the selection by using the check box in the table header.

i_round_blueYou cannot change this setting if the probe is not connected.

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.

i_round_redUse with caution. It can create huge data files. We recommend that you only use this setting for a short time.

i_round_blueIn a cluster, PRTG stores the result in the PRTG data directory of the master node.

Sensor Display

Sensor Display

Sensor Display



Primary Channel

Select a channel from the list to define it as the primary channel. In the device tree, PRTG displays the last value of the primary channel below the sensor's name. The available options depend on what channels are available for this sensor.

i_round_blueYou can set a different primary channel later by clicking b_channel_primary below a channel gauge on the sensor's Overview tab.

Graph Type

Define how this sensor shows different channels:

  • 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.
    i_round_redYou 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. PRTG stacks all channels with this unit 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

Primary Toplist



Primary Toplist

Define which Toplist is the primary Toplist of the sensor:

  • Top Talkers
  • Top Connections
  • Top Protocols
  • [Any custom Toplists you add]

i_round_bluePRTG 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 b_inherited_enabled under the corresponding setting name to disable the inheritance and to display its options.

i_square_cyanFor more information, see section Inheritance of Settings.


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.

i_square_cyanFor more information, see section Toplists.

Filter Rules

The following filter rules apply to all Flow (NetFlow, jFlow, sFlow, IPFIX) and Packet Sniffer sensors.

i_square_cyanFor more information, see section Filter Rules for Flow, IPFIX, and Packet Sniffer Sensors.


Possible Filter Values


IP address or DNS name


Any number


IP address or DNS name


Any number


IP address or DNS name


Any number


Transmission Control Protocol (TCP), User Datagram Protocol (UDP), Internet Control Message Protocol (ICMP), Open Shortest Path First (OSPF), any number


Type of Service (ToS): any number


Differentiated Services Code Point (DSCP): any number

The following filter rules apply to Packet Sniffer sensors only.


Possible Filter Values


Physical address


Physical address


Physical address


IPV4, ARP, RARP, APPLE, AARP, IPV6, IPXold, IPX, any number


IEEE 802.1Q VLAN Priority Code Point


IEEE 802.1Q VLAN Identifier


IPv6 Traffic Class: corresponds to TOS used with IPv4


IPv6 Flow Label

Channel List

i_round_blueWhich channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.




The traffic by type according to the channel definition


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


All traffic for which no channel is defined


The total traffic

i_round_blueThis channel is the primary channel by default.


i_square_blueKNOWLEDGE BASE

What security features does PRTG include?

Where is the volume line in graphs?