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

The Packet Sniffer sensor monitors the headers of data packets that pass a local network card using a built-in packet sniffer. You can choose from predefined channels.

i_round_blueThis sensor analyzes only header traffic.

Packet Sniffer Sensor

Packet Sniffer 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
  • French: Reniflage de paquets
  • German: Packet Sniffer
  • Japanese: パケットスニファー
  • Portuguese: Sniffer de pacotes
  • Russian: Анализатор пакетов
  • Simplified Chinese: 数据包嗅探程序
  • Spanish: Analizador de paquetes


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 supports IPv6.

Network Mapper

  • Using Network Mapper (Nmap) on the parent probe system might cause high CPU load. If you have this issue, restarting the PRTG probe service might help.

Knowledge Base


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.

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.

Channel Configuration

Channel Configuration

Channel Configuration



Channel Selection

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 Virtual Network Computing (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:

  • No (i_channel_selection_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 (i_channel_selection_yes): Count all traffic of this group and summarize it in one channel.
  • Detail (i_channel_selection_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.
    i_round_redExtensive 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.

i_square_cyanYou can change the default configuration for groups and channels. For more information, see the Knowledge Base: How can I change the default groups and channels for flow and Packet Sniffer sensors?

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

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

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 from chat and instant messaging (IRC, AIM)


The traffic from Citrix applications


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


The traffic from file transfer (FTP/P2P)


The traffic from network services (DHCP, DNS, Ident, ICMP, SNMP)


The internet mail traffic (IMAP, POP3, SMTP)


The traffic from NetBIOS communication


The traffic from various other protocols (UDP, TCP)

Remote Control

The traffic from remote control applications (RDP, SSH, Telnet, Virtual Network Computing (VNC))


The total traffic

i_round_blueThis channel is the primary channel by default.


The traffic from various other sources


The traffic from the web (HTTP, HTTPS)


i_square_blueKNOWLEDGE BASE

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?