PRTG Manual: Port Sensor

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.

If 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

Shows tags that the sensor inherits from its parent device, parent group, and parent probe.

This setting is for your information only. You cannot change it.

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.

It is not possible to enter tags with a leading plus (+) or minus (-) sign, nor tags with parentheses (()) or angle brackets (<>).

For 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:

▪portsensor

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 () to the highest priority ().

Timeout (Sec.)

Enter a timeout in seconds for the request. Enter an integer. The maximum timeout value is 900 seconds (15 minutes).

If the reply takes longer than this value, the sensor cancels the request and shows a corresponding error message.

Port

Enter the number of the port to which this sensor connects. Enter an integer.

Transport-Level Security

Define the security of the connection:

▪Do not use transport-level security (default): Establish the connection without connection security.

▪Use transport-level security: Establish the connection with the strongest Secure Sockets Layer (SSL)/Transport Layer Security (TLS) method that the target device provides.

Goal

Define how the sensor reports on the port:

▪Open: Show the Up status if the port is open, and the Down status if the port is closed.

▪Closed: Show the Up status if the port is closed, and the Down status if the port is open.

Command Handling

This setting is only visible if you select Open above. Define whether the sensor sends a command after it opens the port:

▪Do not send a command: Only check if a connection to the port is possible.

▪Send a command: Open a Telnet session to the respective port and send a command.
You cannot use this option if the target device is a web server.

Command

This setting is only visible if you select Send a command above. Enter the command that the sensor sends to the respective port in a Telnet session. Enter a string.

You cannot use line breaks. You can only use a simple Telnet command in a single line.

Response

Define if the sensor further processes the response:

▪Ignore response: Do not check the response.

▪Check response code (integer): Check if the response matches a defined response code. Define the response code below.

▪Check response text: Check if the response matches a defined response text. Define the response text below.

Allowed Response Code

This setting is only visible if you select Check response code (integer) above. Enter the code that the target device must return. If the target device does not return this code, the sensor shows the Down status. Enter an integer.

Check for Keywords (positive)

This setting is only visible if you select Check response text above. Check if the response contains a specific keyword. If the response does not contain the keyword, the sensor shows the Down status.

▪Disable: Do not check for positive keywords.

▪Enable keyword check (positive): Check if a specific keyword exists in the received value. Define the keyword below.

Response Must Include (Down Status if Not Included)

This setting is only visible if you select Enable keyword check (positive) above. Define the search string that the response must contain. You can enter a simple string in plain text or a regular expression (regex).

The search string must be case sensitive.

If the data does not include the search pattern, the sensor shows the Down status.

Search Method

Define the method with which you want to provide the search string:

▪Simple string search: Search for a simple string in plain text.

The characters * and ? work as placeholders. * stands for no number or any number of characters and ? stands for exactly one character. You cannot change this behavior. The literal search for these characters is only possible with a regex.

▪Regular expression: Search with a regex.

PRTG supports Perl Compatible Regular Expression (PCRE) regex. For more details, see section Regular Expressions.

Check for Keywords (negative)

This setting is only visible if you select Simple string search above. Check if the response does not contain a specific keyword. If the response does contain the keyword, the sensor shows the Down status.

▪Disable: Do not check for negative keywords.

▪Enable keyword check (negative): Check if a specific keyword does not exist in the received value. Define the keyword below.

Response Must Not Include (Down Status if Included)

This setting is only visible if you select Enable keyword check (negative) above. Define the search string that the response must not contain. You can enter a simple string in plain text or a regex.

The search string must be case sensitive.

If the data does include the search pattern, the sensor shows the Down status.

Search Method

Define the method with which you want to provide the search string:

▪Simple string search: Search for a simple string in plain text.

The characters * and ? work as placeholders. * stands for no number or any number of characters and ? stands for exactly one character. You cannot change this behavior. The literal search for these characters is only possible with a regex.

▪Regular expression: Search with a regex.

PRTG supports Perl Compatible Regular Expression (PCRE) regex. For more details, see section Regular Expressions.

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 and Result of Sensor [ID].Data.txt. This setting is for debugging purposes. PRTG overwrites these files with each scanning interval.

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, 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.

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

Available

The time until a request to a port is accepted in milliseconds (msec)

This channel is the primary channel by default.

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