PRTG Manual: Syslog Receiver 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:

▪syslogsensor

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 ().

Port

Enter the number of the port on which the sensor listens for Syslog messages. The default port is 514. Enter an integer.

We recommend that you use the default value.

Purge Messages After

Define how long PRTG stores received Syslog messages for analysis. Select a period of time from the dropdown list.

Include Filter

Define if you want to filter Syslog messages. If you leave this field empty or use the keyword any, the sensor processes all data. To only include specific types of messages, define filters using a special syntax.

Exclude Filter

Define which types of Syslog messages the sensor discards and does not process. To exclude specific types of messages, define filters using a special syntax.

Warning Filter

Define which types of Syslog messages count for the Warnings channel. To categorize received messages as warning messages, define filters using a special syntax.

The sensor collects messages until a scanning interval ends. As long as the scanning interval is running, the sensor does not change its status. By default, the sensor changes to the Warning status after a scanning interval finishes and there was at least one warning message (and no error message) during this scanning interval. The sensor shows the Warning at least until the succeeding scanning interval finishes. If the sensor does not receive any warning or error message in this scanning interval, its status changes to the Up status again with the start of the next scanning interval.

Error Filter

Define which types of Syslog messages count for the Errors channel. To categorize received messages as error messages, define filters using a special syntax.

The sensor collects messages until a scanning interval ends. As long as the scanning interval is running, the sensor does not change its status. By default, the sensor changes to the Down status after a scanning interval finishes and there was at least one error message during this scanning interval. The sensor shows the Down status at least until the succeeding scanning interval finishes. If the sensor does not receive any warning or error message in this scanning interval, its status changes to the Up status again with the start of the next scanning interval.

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.

Result Handling

Define what PRTG does with the sensor result:

▪Discard result (recommended): Do not store the sensor result.

▪Store result: Store the last sensor result in the \Logs\debug subfolder of the PRTG data directory on the probe system. The file name is Sensor [ID]_[Date].log. This setting is for debugging purposes.
Use with caution. We recommend that you only use this setting for a short time because it can create huge data files.

source[ip]

Enter an IP address where the messages come from. IP masks and ranges are also possible.

▪source[10.0.23.50]

▪source[10.0.23.10-50]

▪source[10.0.23.10/24]
 

facility[number]

Enter any number or range from 0 to 23 specifying the program type that sends the message.

▪facility[2]

▪facility[5-7]

▪facility[5] OR facility[6]
 

severity[number]

Enter any number or range from 0 (emergency) to 7 (debug) specifying the message type.

▪severity[4]

▪severity[1-3]

▪severity[1] AND severity[2]
 

hostname[text]

Enter any string that specifies the hostname of a device in the message.

▪hostname[www.example.com]
 

tag[text]

Enter any string that specifies the tag of a program or process in the message.

▪tag[su]
 

appname[text]

Enter any string that specifies the appname part of the message.

▪appname[myproc]

▪appname[demo] AND msgid[m42]
 

procid[text]

Enter any string that specifies the process identifier part of the message.

▪procid[1860]
 

msgid[text]

Enter any string that specifies the message identifier part of the message.

▪msgid[ID47]
 

message[parttext]

Enter any string that specifies the message part of the message. (Any substring matches. This value is case insensitive.)

▪message[Error]
 

data[id,param,value]

This checks the SD-ID block of the message's structured data for a parameter matching the specified value.

▪data[[email protected],eventSource,Application]
 

data[parttext]

This checks if the specified substring matches structured data as displayed in the corresponding table.

▪data[[email protected]]
 

data[id,param]

This checks if the parameter exists in the specified ID element.

▪data[[email protected],eventSource]
 

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

Drops

The number of dropped packets per second on the syslog port

Errors

The number of messages categorized as "error" per second

Messages

The number of received Syslog messages per second

This channel is the primary channel by default.

Warnings

The number of messages categorized as "warning" per second