The SNMP Traffic sensor monitors traffic on a device via the Simple Network Management Protocol (SNMP).
You can create the sensor on a device that provides traffic data.
SNMP Traffic Sensor
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
Sensor in Other Languages
Dutch: SNMP Verkeer
French: Trafic (SNMP)
German: SNMP Datenverkehr
Japanese: SNMP トラフィック
Portuguese: Tráfego (SNMP)
Russian: Трафик по SNMP
Simplified Chinese: SNMP 流量
Spanish: Tráfico (SNMP)
Remarks
You can define the displayed sensor name with port name templates in the SNMP compatibility options of the parent device.
We recommend that you select SNMP v2c (most common) or SNMP v3 in the credentials for SNMP devices of the parent device (if supported by the target device). SNMP v1 does not support 64-bit counters, which may result in invalid data. For details, see the Knowledge Base: SNMP Traffic sensor suddenly drops at 610Mbps
It might not work to query data from a probe device via SNMP (querying localhost, 127.0.0.1, or ::1). Add this device to PRTG with the IP address that it has in your network and create the SNMP sensor on this device instead.
This sensor supports the IPv6 protocol.
This sensor has a very low performance impact.
The auto-discovery always creates SNMP Traffic sensors for all interfaces whose SNMP traffic counters are above 0. As a result, every interface that has had traffic since the last restart of the target device is added, even if it is currently disconnected or disabled. For details, see the Knowledge Base: How does auto-discovery with SNMP Traffic sensors work?
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.
Traffic Specific
Setting
Description
Interface Number
Select the ports on SNMP devices with multiple interfaces that you want to monitor. PRTG creates one sensor for each port that you select.
Enable check boxes in front of the respective lines to select the items. Use the check box in the table header to select all items or to cancel the selection. In large tables, use the search function in the upper-right corner.
You can see the connection status of an interface in the respective table column.
You can select interfaces and cancel the selection by clicking Select all connected interfaces, Select all disconnected interfaces, and Deselect all interfaces.
Name for Traffic In Channel
For the standard channel Traffic In, enter the channel name here. The sensor shows it in graphs and tables. You can change this description and the description of all other channels in the channel settings later.
Name for Traffic Out Channel
For the standard channel Traffic Out, enter the channel name here. The sensor shows it in graphs and tables. You can change this description and the description of all other channels in the channel settings later.
Name for Traffic Total Channel
For the standard channel Traffic Total, enter the channel name here. The sensor shows it in graphs and tables. You can change this description and the description of all other channels in the channel settings later.
Basic Sensor Settings
Click the Settings tab of a sensor to change its settings.
If 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?
This setting is for your information only. You cannot change it.
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 (<>).
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
snmptrafficsensor
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 ().
Usually, a sensor connects to the IP Address/DNS Name of the parent device. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings.
Traffic Specific
Traffic Specific
Setting
Description
Interface Number
Shows the number and name of the interface in the physical device that this sensor monitors.
PRTG shows this value for reference purposes only. We strongly recommend that you only change it if the Paessler support team explicitly asks you to do so. Wrong usage can result in incorrect monitoring data.
Additional Channels
By default, each SNMP Traffic sensor creates the channels Traffic In, Traffic Out, and Traffic Total. Select additional channels for all interfaces. Click the respective channel names to mark the channels and to monitor their data.
You can choose between the following additional channels:
Errors in and Errors out: The number of incoming and outgoing packets that could not be delivered because of errors.
Discards in and Discards out: The number of discarded incoming and outgoing packets even though no errors have been detected.
Unicast packets in Unicast packets out: The number of unicast packets that have been delivered.
Non Unicast packets in and Non Unicast packets out (32-bit only): The number of non-unicast packets that have been delivered.
Multicast packets in and Multicast packets out (64-bit only): The number of delivered packets that were addressed to a multicast address.
Broadcast packets in and Broadcast packets out (64-bit only): The number of delivered packets that were addressed to a broadcast address
Unknown Protocols: The number of received packets that were discarded because of an unknown or unsupported protocol.
You cannot delete additional channels later. You can only disable them.
If the sensor shows the Warningstatus with the message Channels not available, you can disable the affected channels to remove the warning.
Connection Status Handling
Define how PRTG reacts when an interface is operational. An interface that is not operational is, for example, an Ethernet port on a switch with no cable plugged in. This setting is valid for all selected interfaces. Choose between:
Show down status for all disconnected states: Show the Down status for a disconnected interface. This applies if the ifOperStatus of the interface is not "up".
Show down status when disconnected, ignore when deactivated: Show the Down status for a disconnected interface only if it is not deliberately deactivated in the configuration. This applies if the ifOperStatus of the interface is not "up" and the ifAdminStatus is "up". So the sensor stays in the Up status when the interface has been deactivated.
Ignore all disconnected states: Show the Up status. Monitoring is discontinued without notice.
PRTG shows this value for reference purposes only. We strongly recommend that you only change it if the Paessler support team explicitly asks you to do so. Wrong usage can result in incorrect monitoring data.
Sensor Display
Sensor Display
Setting
Description
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).
Show in and out traffic as positive and negative area graph: Show channels for incoming and outgoing traffic as positive and negative area graph. This visualizes your traffic in a clear way. You cannot use this option in combination with manual Vertical Axis Scaling (available in the channel settings). Manual scaling is not possible if you choose this option. You cannot show a positive/negative graph for a channel if you choose to display its data in percent of maximum (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.
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 under the corresponding setting name to disable the inheritance and to display its options.
For more information, see section Root Group Settings, section Scanning Interval.
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
For more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.
Access Rights
Access Rights
For more information, see section Root Group Settings, section Access Rights.
Channel Unit Configuration
Channel Unit Configuration
For more information, see section Root Group Settings, section Channel Unit Configuration.
Channel List
Which channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.
Channel
Description
Discards In
The number of incoming discards per second
Discards Out
The number of outgoing discards per second
Downtime
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
Errors In
The number of incoming errors per second
Errors Out
The number of outgoing errors per second
Non-Unicast In
The number of incoming non-unicast packets per second
Non-Unicast Out
The number of outgoing non-unicast packets per second
Traffic In
The incoming traffic
Traffic Out
The outgoing traffic
Traffic Total
The total traffic
This channel is the primary channel by default.
Unicast In
The number of incoming unicast packets
Unit
The number of outgoing unicast packets per second
Unknown Protocols In
The number of incoming, unknown protocols per second
More
KNOWLEDGE BASE
How does auto-discovery with SNMP Traffic sensors work?