The SNMP RMON sensor monitors traffic on a device using the Remote Monitoring (RMON) standard via the Simple Network Management Protocol (SNMP).

i_round_blueYou can create it on an SNMP-compatible device that provides traffic data via RMON. Depending on the data that the device returns, PRTG displays traffic data for each port in different channels, which allows a detailed analysis. If available, the sensor queries 64-bit counters.



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 RMON
  • French: RMON (SNMP)
  • German: SNMP RMON
  • Japanese: SNMP RMON
  • Portuguese: RMON (SNMP)
  • Russian: RMON по SNMP
  • Simplified Chinese: SNMP RMON
  • Spanish: RMON (SNMP)


  • 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.
  • This sensor supports IPv6.
  • This sensor has a very low performance impact.

Basic Sensor 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

The 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:

  • snmprmon


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).

RMON Specific

RMON Specific

RMON Specific




The number of the interface port that this sensor monitors.

Channel Mask

Describes which channels are available. This information might be useful for the Paessler support team.

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.

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

i_round_blueWhich channel units are available depends on the sensor type and the available parameters. If no configurable channels are available, this field shows No configurable channels.

Channel Unit Configuration

Channel Unit Configuration

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

Channel List

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



Broadcast Packets

The number of broadcast packets


The number of collisions

CRC Errors

The number of CRC errors


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

Drop Events

The number of drop events


The number of fragments


The number of jabbers

Multicast Packets

The number of multicast packets

Oversize Packets

The number of oversize packets


The number of packets

Packets <= 64 Byte

The number of packets with less than or equal to 64 bytes

Packets 65 - 127 Bytes

The number of packets with 65 - 127 bytes

Packets 128 - 255 Bytes

The number of packets with 128 - 255 bytes

Packets 256 - 511 Bytes

The number of packets with 256 - 511 bytes

Packets 512 - 1023 Bytes

The number of packets with 512 - 1023 bytes

Packets 1024 - 1518 Bytes

The number of packets with 1024 - 1518 bytes


The transmitted bytes

i_round_blueThis channel is the primary channel by default.

Undersize Packets

The number of undersize packets


i_square_blueKNOWLEDGE BASE

What value does the Transmitted channel of an RMON sensor show?

Automatically update port name and number for SNMP Traffic sensors when the device changes them

Where is the volume line in graphs?

What security features does PRTG include?

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