PRTG Manual: SNMP Custom Table Sensor
The SNMP Custom Table sensor monitors entries from a table that is provided via the Simple Network Management Protocol (SNMP). You can create one new sensor per table row. For each sensor, you can define up to ten channels. Each channel shows the value of one defined table column.
The sensor can show the following:
- Numerical values in up to 10 channels per table row
Which channels the sensor actually shows might depend on the monitored device and the sensor setup.
The SNMP Library sensor automatically creates SNMP Custom Table sensors when the imported Management Information Base (MIB) file contains tables.
- Dutch: SNMP Aangepaste Tabel
- French: Table SNMP personnalisée
- German: SNMP (Benutzerdef. Tabelle)
- Japanese: SNMP カスタムテーブル
- Portuguese: Tabela customizada do SNMP
- Russian: Нестандартная таблица SNMP
- Simplified Chinese: SNMP 自定义表
- Spanish: Tabla de SNMP personalizado
- 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 low performance impact.
- See the Knowledge Base: How do I find out which OID I need for an SNMP Custom sensor?
- See the Knowledge Base: What can I monitor with the SNMP Custom Table Sensor?
The Add Sensor dialog appears when you manually add a new sensor to a device. It only shows the setting fields that are required for creating the sensor. Therefore, you do not see all setting fields in this dialog. You can change (nearly) all settings in the sensor's Settings tab later.
PRTG creates one SNMP Custom Table sensor for each table row that you select in the Add Sensor dialog. The settings you select are valid for all sensors that you create when you finish this dialog.
The following settings in the Add Sensor dialog differ in comparison to the sensor's Settings tab.
Setting |
Description |
---|---|
Table OID |
Enter the object identifier (OID) of the SNMP table that you want to monitor. The OID needs to point directly to an object that represents an SNMP table. Once you have created the sensor, you cannot change this value. It is shown for reference purposes only. If you need to change this value, add the sensor anew.
|
Setting |
Description |
---|---|
Sensor Name |
Enter a meaningful name to identify the sensor. You can use the placeholders [tablename] and [rowidentifier]. They are replaced with the name of the table and the identifying value of the chosen row respectively. You can select the column that provides the row identifier in the Identification Column option below. You can also enter a valid OID that is part of a different SNMP table, for example, [1.3.6.1.2.1.2.2.1.2], to query information that is not contained in the current table. The same index as in the original table is added to the OID. |
Setting |
Description |
---|---|
Table |
Select the relevant table rows in which you find the data that you want to monitor. You see a list with the names of all items that you can monitor. Add check marks in front of the respective lines to select the desired items. You can also use the check box in the table header to select all items or cancel the selection.
PRTG shows you the table that the OID you entered before returns. To better find what you want to monitor, particularly in large tables, use the search function in the upper-right corner. |
Identification Column |
Define the identification column for the SNMP Custom Table sensors that you want to create. The sensor uses this column to uniquely identify each table row. This column should preferably be unique because it allows the sensor to keep track of changing indexes. The value of the column that you selected as identification column replaces the [rowidentifier] in the sensor name. This lets you distinguish sensors that are created for the same SNMP table.
|
Channel #2 – #10 |
You can create up to 10 different channels for this sensor. You have to define at least one data channel, so you see all available settings for Channel #1 without enabling it manually. Additionally, you can define Channel #2 up to Channel #10. To do so, choose between:
It is not possible to enable or disable channels after creating this sensor.
|
Value Type |
Select the expected type of results in this channel:
See below for other channel settings that you can also change after sensor creation.
|
Click the Settings tab of a sensor to change its settings.
Usually, a sensor connects to the IP Address or DNS Name of the parent device on which you created the sensor. See the device settings for details. For some sensors, you can explicitly define the monitoring target in the sensor settings. See below for details on available settings.
Setting |
Description |
---|---|
Sensor Name |
Enter a meaningful 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. This setting is shown for your information only and cannot be changed here. |
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:
|
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 ( |
SNMP Table
Setting |
Description |
---|---|
Table OID |
Shows the OID of the SNMP table that this sensor monitors. Once you have created the sensor, you cannot change this value. It is shown for reference purposes only. If you need to change this value, add the sensor anew. |
Setting |
Description |
---|---|
Identifier |
This is the value of the column that you selected as the Identification Column during sensor creation. It is also displayed in the sensor name to distinguish it from other sensors you created for the same table with other table rows. You can change the identifier if you want to. |
Identification Column |
Shows the table column that you chose as identification column. Once you have created the sensor, you cannot change this value. It is shown for reference purposes only. If you need to change this value, add the sensor anew. |
Channel #x Name |
Enter a name for the channel in which the sensor shows the desired result. Enter a string. |
Channel #x Column |
Select the table column that together with the table row points to the value that you want to monitor in this channel. You can choose between the available columns of the table that you monitor. |
Channel #x Value Type |
Shows the value type of the data that this sensor receives in this channel. Once you have created the sensor, you cannot change this value. It is shown for reference purposes only. If you need to change this value, add the sensor anew. |
Channel #x Unit |
Define the unit of the data that this sensor receives in this channel:
|
Channel #x Custom Unit |
This setting is only visible if you select the Custom unit option above. Define a unit for the channel value. Enter a string. |
Channel #x Lookup |
This setting is only visible if you select the Lookup option above. Select a lookup file that you want to use with this channel. |
Channel #x+1 |
Shows if you enabled or disabled a channel. Once you have created the sensor, you cannot change this value. It is shown for reference purposes only. If you need to change this value, add the sensor anew. |
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:
|
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 the following settings are inherited from objects that are higher in the hierarchy. You should 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. You then see the options described below.
For more information, see section Inheritance of Settings.
Click to interrupt the inheritance.
Setting |
Description |
---|---|
Scanning Interval |
Select a scanning interval from the dropdown list. The scanning interval determines the amount of time that the sensor waits between two scans. Choose from:
|
If a Sensor Query Fails |
Select the number of scanning intervals that the sensor has time to reach and to check a device again if a sensor query fails. Depending on the option that you select, the sensor can try to reach and to check a device again several times before the sensor shows the Down status. This can avoid false alarms if the monitored device only has temporary issues. For previous scanning intervals with failed requests, the sensor shows the Warning status. Choose from:
|
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.
Setting |
Description |
---|---|
Schedule |
Select a schedule from the list. You can use schedules to monitor during a certain time span (days or hours) every week. Choose from:
|
Maintenance Window |
Select if you want to set up a one-time maintenance window. During a maintenance window, monitoring stops for the selected object and all child objects. They show the Paused status instead. Choose between:
|
Maintenance Begins |
This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the start date and time of the one-time maintenance window. |
Maintenance Ends |
This setting is only visible if you enable Set up a one-time maintenance window above. Use the date time picker to enter the end date and time of the one-time maintenance window. |
Dependency Type |
Select a dependency type. You can use dependencies to pause monitoring for an object depending on the status of a different object. You can choose from:
|
Dependency |
This setting is only visible if you enable Select a sensor above. Click |
Dependency Delay (Sec.) |
This setting is only visible if you enable Select a sensor above. Define a time span in seconds for the dependency delay. After the master sensor for this dependency returns to the Up status, PRTG additionally delays the monitoring of the dependent objects by the time span you define. This can prevent false alarms, for example, after a server restart or to give systems more time for all services to start. Enter an integer value.
|
Click to interrupt the inheritance.
Setting |
Description |
---|---|
User Group Access |
Define the user groups that have access to the sensor. You see a table with user groups and group access rights. The table contains all user groups in your setup. For each user group, you can choose from the following group access rights:
|
KNOWLEDGE BASE
What SNMP sensors does PRTG offer?
My SNMP sensors don't work. What can I do?
What can I monitor with the SNMP Custom Table Sensor?
Can I monitor UPS systems complying with the UPS MIB (RFC-1628) with PRTG?
How do I find out which OID I need for an SNMP Custom sensor?
For more information about sensor settings, see the following sections: