PRTG Manual: SNMP Traffic Sensor
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.
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
▪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)
▪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?
▪See the Knowledge Base: Automatically update port name and number for SNMP Traffic sensors when the device changes them
▪See the Knowledge Base: Where is the volume line in graphs?
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.
|
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. |
Click the Settings tab of a sensor to change its settings.
Setting |
Description |
---|---|
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.
|
Parent Tags |
Shows tags that the sensor inherits from its parent device, parent group, and parent probe.
|
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.
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 ( |
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.
Setting |
Description |
---|---|
Interface Number |
Shows the number and name of the interface in the physical device that this sensor monitors.
|
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.
|
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. |
Alias Availability |
Shows if an alias is available for automatic port name updates.
|
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.
|
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. ▪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. |
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. |
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 Inheritance of Settings.
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.
For more information, see section Root Group Settings, section Schedules, Dependencies, and Maintenance Window.
For more information, see section Root Group Settings, section Access Rights.
For more information, see section Root Group Settings, section Channel Unit Configuration.
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
|
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 |
KNOWLEDGE BASE
How does auto-discovery with SNMP Traffic sensors work?
▪https://kb.paessler.com/en/topic/85407
Automatically update port name and number for SNMP Traffic sensors when the device changes them
▪https://kb.paessler.com/en/topic/25893
Where is the volume line in graphs?
▪https://kb.paessler.com/en/topic/61272
What security features does PRTG include?
▪https://kb.paessler.com/en/topic/61108
SNMP Traffic sensor suddenly drops at 610Mbps
▪https://kb.paessler.com/en/topic/67503
My SNMP sensors don’t work. What can I do?