<%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_blueThe 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


  • This sensor has a very high performance impact. We recommend that you use no more than 50 of this sensor on each probe.
  • By default, this sensor works only on a probe device.
  • This sensor supports IPv6.
  • 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.

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.

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.

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

Basic Sensor Settings



Sensor Name

Enter a 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.

i_round_blueIf 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?

Parent Tags

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

i_round_blueThis setting is for your information only. You cannot change it.


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.

i_round_blueIt is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

i_round_blueFor 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
  • sniffersensor


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 (i_priority_1) to the highest priority (i_priority_5).

Sniffer Specific

i_square_cyanFor detailed 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. If you enable this setting, 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 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 (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 details, 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, 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.

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 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.
    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 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

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.

Scanning Interval

Scanning Interval

Scanning Interval

i_square_cyanFor more information, see section Root Group Settings, section Scanning Interval.

Schedules, Dependencies, and Maintenance Window

i_round_blueYou 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

Schedules, Dependencies, and Maintenance Window

i_square_cyanFor more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.

Access Rights

Access Rights

Access Rights

i_square_cyanFor more information, see section Root Group Settings, section Access Rights.

Channel Unit Configuration

Channel Unit Configuration

Channel Unit Configuration

i_square_cyanFor more information, see section Root Group Settings, section Channel Unit Configuration.


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 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, 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?