PRTG Manual: SSH Remote Ping Sensor

Performance impact

This sensor has a high performance impact. We recommend that you use no more than 200 of this sensor on each probe.

Credentials

This sensor requires credentials for Linux/Solaris/macOS (SSH/WBEM) systems in the settings of the parent device.

Distributions

This sensor does not support all Linux/Unix and macOS distributions.

IPv4

This sensor only supports IPv4.

Knowledge Base

• Knowledge Base: Which encryption algorithms do PRTG SSH sensors support?
• Knowledge Base: SSH and SFTP sensors in Unknown status

Target

Enter the Domain Name System (DNS) name or IP address of the target device the ping is sent to. The sensor remotely connects to the parent device it is created on via SSH, then performs a ping request from this remote device to the target device or server. Enter a string.

Packet Size (Bytes)

Enter the packet size for the ping in bytes. You can enter any value between 1 and 10000. Enter an integer.

We recommend that you use the default value.

Packet Count

Enter the number of packets that the sensor sends with each scanning interval.

Custom Parameter

Optionally, enter additional parameters that the sensor adds at the end of the ping command. Enter a string or leave the field empty.

Do not use parameters that change the output format of the result to make sure that it can still be parsed. You cannot enter an additional command.

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. The maximum timeout value is 900 seconds (15 minutes).

Make sure that the connection timeout is a value that is higher than the shell timeout to avoid potential errors.

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.

Make sure that the shell timeout is a value that is lower than the connection timeout to avoid potential errors.

SSH Port Inheritance

Define which port this sensor uses for the SSH connection:

• Inherit port 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.
• Do not inherit port (enter a custom SSH port): Define a custom port number below and do not use the port number from the parent device settings.

Custom SSH Port

This setting is only visible if you select Do not inherit port (enter a custom SSH port) 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:

• 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.

We strongly recommend that you use the default SSH engine.

The option you select here overrides the selection of the SSH engine in a higher object: a parent device, group, probe, or root.

Result Handling

Define what PRTG does with the sensor result:

• Discard result (default): 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.

This option is not available when the sensor runs on the hosted probe of a PRTG Hosted Monitor instance.

In a cluster, PRTG stores the result in the PRTG data directory of the master node.

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.

You can set a different primary channel later by clicking 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.
  You 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.

Avg. Response

The average response time measured from the remote device

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

Max Response

The maximum response time measured from the remote device

Min Response

The minimum response time measured from the remote device

Packet Loss

The packet loss (%)

This channel is the primary channel by default.