PRTG Manual: SSH Script Advanced Sensor
The SSH Script Advanced sensor connects to a Linux/Unix system via Secure Shell (SSH) and executes a script file that is located on the target system. This option is available as part of the PRTG API.
For a detailed list and descriptions of the channels that this sensor can show, see section Channel List.
▪Dutch: SSH Script Geavanceerd
▪French: Script (SSH) avancé
▪German: SSH-Skript (Erweitert)
▪Japanese: SSH スクリプト(詳細)
▪Portuguese: Script (avançado) (SSH)
▪Russian: Расширенный скрипт SSH
▪Simplified Chinese: 高级 SSH 脚本
▪Spanish: Script (avanzado) (SSH)
▪This sensor has a very high performance impact. Use it with care. We recommend that you use no more than 50 sensors of this sensor type on each probe.
▪For security reasons, you must store the script file in the /var/prtg/scriptsxml directory on the target system. Make sure that the script has executable rights.
▪This sensor requires credentials for Linux/Solaris/macOS (SSH/WBEM) systems in the settings of the parent device.
▪This sensor cannot support all Linux/Unix and macOS distributions.
▪This sensor does not officially support more than 50 channels. Depending on the data used with this sensor, you might exceed the maximum number of supported channels. In this case, PRTG tries to display all channels. Be aware, however, that you experience limited usability and performance.
▪This sensor only supports the IPv4 protocol.
▪For details about the return value format, see section Custom Sensors.
▪See the Knowledge Base: Which encryption algorithms do PRTG SSH sensors support?
▪See the Knowledge Base: SSH and SFTP sensors in Unknown status
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.
Sensor Settings
Setting |
Description |
---|---|
Script |
Select a script file from the dropdown list. It shows all script files that are available in the /var/prtg/scriptsxml directory on the target Linux/Unix system. For a script file to appear in this list, store the target file in this directory.
|
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: ▪sshscript |
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 ( |
Credentials for Script Sensors
Click to interrupt the inheritance.
Setting |
Description |
---|---|
Placeholder 1 Description |
Enter a description for Placeholder 1, for example information about the purpose or content of the placeholder. |
Placeholder 1 |
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder1 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings. |
Placeholder 2 Description |
Enter a description for Placeholder 2, for example information about the purpose or content of the placeholder. |
Placeholder 2 |
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder2 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings. |
Placeholder 3 Description |
Enter a description for Placeholder 3, for example information about the purpose or content of the placeholder. |
Placeholder 3 |
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder3 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings. |
Placeholder 4 Description |
Enter a description for Placeholder 4, for example information about the purpose or content of the placeholder. |
Placeholder 4 |
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder4 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings. |
Placeholder 5 Description |
Enter a description for Placeholder 5, for example information about the purpose or content of the placeholder. |
Placeholder 5 |
Enter a value for the placeholder. PRTG inserts the value for the script execution if you add %scriptplaceholder5 in the argument list. PRTG does not display the value in the sensor log or the sensor's settings. |
Setting |
Description |
---|---|
Script |
Shows the name of the script that the sensor executes with each scanning interval.
|
Parameters |
If your script file catches command-line parameters, you can define them here. You can use also placeholders. Enter a string or leave the field empty.
|
Mutex Name |
Define a mutual exclusion (mutex) name for the process. Enter a string or leave the field empty.
|
Setting |
Description |
---|---|
Connection Timeout (Sec.) |
Define a timeout in seconds for the connection. This is the time that the sensor waits to establish a connection to the host. Keep this value as low as possible. Enter an integer.
|
Shell Timeout (Sec.) |
Define a timeout in seconds for the shell response. This is the time in seconds the sensor waits for the shell to return a response after it has sent its specific command (for example, cat /proc/loadavg). The maximum value is 300 seconds (5 minutes). Enter an integer.
|
SSH Port |
Define which port this sensor uses for the SSH connection: ▪Inherit port number from parent device (default): Use the port number as defined in the Credentials for Linux/Solaris/macOS (SSH/WBEM) Systems section of the parent device settings. ▪Enter custom port number: Define a custom port number below and do not use the port number from the parent device settings. |
Use Port Number |
This setting is only visible if you select Enter custom port number above. Enter the port number (between 1 and 65535) that this sensor uses for the SSH connection. Enter an integer. |
SSH Engine |
Select the SSH engine that you want to use to access data with this SSH sensor. Choose between: ▪Inherit from parent device (default): Use the SSH engine that you defined in the parent device settings or higher up in the object hierarchy. If you have not changed the SSH engine, this is the recommended option. ▪Default: This is the default SSH engine. It provides the best performance and security. It is set by default in objects that are higher up in the hierarchy, so usually you can keep the Inherit from parent device (default) option. ▪Compatibility mode (deprecated): Use this only if the default SSH engine does not work on a target device. The compatibility mode is the SSH engine that PRTG used in previous versions. It is deprecated. We will remove this legacy mode soon, so try to get your SSH sensors to run with the default SSH engine.
|
Result Handling |
Define what PRTG does with the sensor result: ▪Discard result: Do not store the sensor result. ▪Store result: Store the last sensor result in the \Logs\sensors subfolder of the PRTG data directory on the probe system. The file names are Result of Sensor [ID].txt, Result of Sensor [ID].Data.txt, and Result of Sensor [ID] (SSHv2).txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval. ▪Store result in case of error: Store the last sensor result only if the sensor shows the Down status.
|
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. |
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.
Which 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.
For more information, see section Root Group Settings, section Channel Unit Configuration.
Escape Special Characters and Whitespaces in Parameters
You need to escape special characters in parameters that you pass to an executable or script and surround them with quotation marks to make sure that the characters are correctly interpreted. PowerShell scripts in particular require adequate escaping so that the parameters are passed in a valid PowerShell syntax. PRTG automatically does most of the escaping for you.
Follow these rules to escape special characters and whitespaces in the parameters fields:
▪Use quotes for parameters that contain whitespaces.
-name "Mr John Q Public"
-name 'Mr John Q Public'
▪Use double quotes for parameters that contain single quotes.
-name "Mr 'John Q' Public"
▪Use single quotes for parameters that contain double quotes.
-name 'Mr "John Q" Public'
▪Use a backslash (\) to escape and pass a literal double quote.
-name pub\"lic
▪Use double quotes for parameters that contain double and single quotes and escape double quotes.
-name "pu'b\"lic"
In SSH scripts, you can use alphanumeric characters and the special characters ".", "_", "-", "=", and "/" outside of quoted strings.
We recommend that you do not pass passwords in parameters. Use placeholders instead. See section Custom Sensors for details.
Which channels the sensor actually shows might depend on the target device, the available components, and the sensor setup.
Channel |
Description |
---|---|
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 |
Execution Time |
The execution time in milliseconds (msec) |
[Value] |
The values that the script file returns in several channels
|
KNOWLEDGE BASE
Which encryption algorithms do PRTG SSH sensors support?
▪https://kb.paessler.com/en/topic/90689
SSH and SFTP sensors in Unknown status
▪https://kb.paessler.com/en/topic/79174
What security features does PRTG include?
▪https://kb.paessler.com/en/topic/61108
What is the Mutex Name in the EXE/Script sensor settings?
▪https://kb.paessler.com/en/topic/6673
How can I test if parameters are correctly transmitted to my script when using an EXE/Script sensor?
▪https://kb.paessler.com/en/topic/11283
How can I show special characters with EXE/Script sensors?
▪https://kb.paessler.com/en/topic/64817
Why do I have to store SQL sensor queries and custom scripts in files on the probe computer?
▪https://kb.paessler.com/en/topic/75372
For which sensor types do you recommend at least Windows Server 2012 R2 and why?