<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: SNMP Custom Sensor

The SNMP Custom sensor monitors a single parameter that is returned by a specific object identifier (OID) via the Simple Network Management Protocol (SNMP).

SNMP Custom Sensor

SNMP 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: SNMP (Klant specifiek)
  • French: SNMP personnalisé
  • German: SNMP (Benutzerdef.)
  • Japanese: SNMP カスタム
  • Portuguese: SNMP (customizado)
  • Russian: Пользовательские параметры SNMP
  • Simplified Chinese: SNMP 自定义
  • Spanish: SNMP (personalizado)


Consider the following remarks and requirements for this sensor:




  • This sensor supports IPv6.

Performance impact

  • This sensor has a very low performance impact.


  • It might not work to query data from a probe device via SNMP (querying localhost,, or ::1). Add this device with the IP address that it has in your network and create the sensor on this device instead.

Knowledge Base

Add Sensor



Channel Name

Enter a name for the channel in which the sensor shows the results for the OID. Enter a string.

i_round_blueYou can change this value later in the channel settings of this sensor.

Unit String

Enter the unit for the values that this sensor returns. Enter a string.

i_round_bluePRTG uses the unit string for display purposes and shows it in graphs, data tables, and gauges.

i_round_blueYou can change this value later in the channel settings of this sensor.

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:

  • snmpcustomsensor

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

OID Settings

OID Settings

OID Settings




Enter the OID of the SNMP object that you want to receive numeric data from.

i_round_blueMost OIDs begin with However, OIDs that start with 1.0, or 1.1, or 1.2 are also allowed. If you want to entirely disable the validation of your entry, add the string norfccheck: to the beginning of the OID, for example, norfccheck:

Value Type

Select the expected numeric type of the results at the OID:

  • Absolute (unsigned integer): Integers without an operational sign, such as 10 or 120.
  • Absolute (signed integer): Integers with an operational sign, such as -12 or 120.
  • Absolute (float): Float values, such as -5.80 or 8.23.
  • Delta (counter): Counter values. PRTG calculates the difference between the last and the current value. PRTG additionally divides the delta value by a time period to indicate a speed value.

i_round_redThis mode only works if the difference between the last and the current value is positive and increases with each scanning interval. This mode does not support negative values and decreasing values.

i_round_blueYou cannot change this value after sensor creation.


If you want to multiply the received data with a certain value, enter the multiplier. Use the default value 1 to not change the received value. Enter an integer.


If you want to divide the received data by a certain value, enter the divisor. Use the default value 1 to not change the received value. Enter an integer.

If Value Changes

Define what the sensor does when its value changes:

  • Ignore (default): Do nothing.
  • Trigger 'change' notification: Send an internal message that indicates a change.
    i_round_blueIn combination with a change trigger, you can use this to trigger a notification if a change occurs.

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.

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.

Channel List

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




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 single numeric value (int64) for a specified OID

i_round_blueThis channel is the primary channel by default.


i_square_blueKNOWLEDGE BASE

How do I find out which OID I need for an SNMP Custom sensor?

What security features does PRTG include?

My SNMP sensors don’t work. What can I do?



SNMP Custom sensor and SNMP Custom Library sensor