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Aurelio, System Admin at Paessler AG

Pages of probes, groups, devices, and sensors have an interface providing tabs. By using the tabs you can navigate through various sub-pages of an object to show your network's status, view monitoring results, or change settings.

Tabs Bar on Sensor PagesTabs Bar on Sensor Pages


The Overview tab shows an overview of the currently selected object and of its sensors. The pages share a common layout, but include different elements, depending on the kind of object you look at:

  • For probes and groups , the Overview tab shows a tree-like view with devices and sensors, a Geo Map, as well as summary graphs for different time spans of the current probe or group.
  • For devices , the Overview tab shows device details, a Geo Map, and summary graphs for different time spans, colored gauges for high priority sensors, as well as a table list of all sensors on this device. Additionally, you see a table list with Recommended Sensors.
    • Note: You can turn off the sensor recommendation (and disable this table list) in System Administration—Monitoring.
    • Note: To display gauges, you have to tag corresponding sensors with 4 stars (**** ) or 5 stars (***** ) in the priority settings. 5 star sensors are represented with bigger gauges than 4 star sensors.
  • For sensors , the Overview tab shows sensor details, current status, colored gauges, sensor graphs for different time spans, a table with all sensor channels, as well as similar sensors which show correlations in your network.
  • Gauges and switches represent sensor values on Overview tabs of devices and channel values on Overview tabs of sensors. They graphically illustrate the current values of a sensor or a channel, so you can use them as a quick status indicator. The red and yellow parts of gauges correspond to the error and warning limits of the respective sensor channel settings. Device overview tabs show gauges of high priority sensors, sensor overview tabs show gauges of all sensor channels (except the Downtime channel), with the primary channel having the biggest gauge. For sensor channels that measure or calculate binary values like on/off or successful/failing using lookups, a switch shows green or red color respectively.

Note: For sensors using lookups, we recommend staying below 120 lookup values in the primary channel to get expressive gauges. For sensors with a priority of 4 stars, the upper limit is around 40 lookup values.

Device Overview Tab with Gauges for High Priority Sensors, Sensors Table List, Geo Map, and Mini GraphsDevice Overview Tab with Gauges for High Priority Sensors, Sensors Table List, Geo Map, and Mini Graphs


Toplists are available for xFlow and Packet Sniffer sensors only. Toplist graphs are displayed right on the sensor overview page. Please see the section Toplists .

Live Data and Data By x Days

Select one of the tabs Live Data (available for sensors only), 2 days , 30 days , or 365 days to display an object's monitoring data live (sensors only), or for different time spans and in more or less detail. The time that graph legends and data tables show depends on the time zone settings for the currently logged in user.

Note: The days mentioned here is the default setting. You can change the shown days of the different graphs under System Administration—User Interface.

2 Days Tab of a Firewall with Overview Graph and Sensor Mini Graphs2 Days Tab of a Firewall with Overview Graph and Sensor Mini Graphs

Live Data and Data By x Days—Probes, Groups, and Devices

For probes, groups, and devices, each of the tabs shows a summary graph for the current object and mini graphs for all sensors on this object, as well as a data table for the current object. There are never more than 50 mini graphs displayed for performance reasons. Hover over a mini graph to see the graph legend.

The summary graph shows the number of alarms as well as three index graphs . These graphs indicate response time, CPU usage, and bandwidth usage for all sensors. Index graphs are similar to a stock index. The shown values are based on the readings of all sensors of this object. PRTG computes these values using statistics and by comparing the values to the highest and lowest readings ever recorded.

The three index graphs shows overall (or global) trends in your network. If these values increase during a specific time frame, then CPU load, bandwidth load, or response time respectively have worsened during this time. For example, a CPU Load Index value of 90% means that the average CPU load for all CPU sensors of your current configuration is at 90% of the highest ever measured CPU usage value.

The following four channels are available in the summary graph:

  • Alarms : Sums up the number of all down states of sensors on this object during the given time span. This graph provides you a bird's eye view of trouble in your network. It cannot be hided.
  • Response Time Index : Indicates request times in your network.
  • CPU Load Index : Indicates the CPU usage in your network.
  • Traffic Index : Indicates the bandwidth usage in your network.

See the More section for a detailed description of the index graphs.

You can hide single channels individually except the "Alarms " channel. Simply remove the check mark symbol in front of a channel name besides the graph, and the according channel's line will disappear. You can also Show all or Hide all channels by clicking on the buttons below the channel names. The graph view will be reset immediately.

Sensor Live Data Tab for a Traffic SensorSensor Live Data Tab for a Traffic Sensor

Live Data and Data By x Days—Sensors

For sensors, the tabs show a graph and data table of the selected sensor. When viewing data of a sensor running on a cluster probe, you can additionally select if you want to show the data of all nodes, or of one specific node only. Please use the Select Cluster Member bar below the tabs.

Note: Multi-node graphs are never displayed filled here, but with single lines only. However, historic data reports can have filled multi-node graphs.

While viewing a sensor graph you can hide single sensor channels individually. Simply remove the check mark symbol in front of a channel name below the graph, and the according channel's line will disappear. You can also Show all or Hide all channels by clicking on the buttons besides the channel names.

Live Data and Data By x Days—Interactive Graphs

On historic data tabs of sensors and in "zoomed graphs in new windows" (see below) of other monitoring objects, graphs are interactive. You can zoom in and scroll along the time axis with the corresponding buttons.

Graph ButtonsGraph Buttons

The following actions for graphs are available:

  • << scrolls one graph window left and >> one graph window right. The scrolled time depends on the graph you select, for example, 2 days on a 2 days graph.
  • < scrolls left and > right on the time axis. The scrolled time depends on the graph you select.
  • + zooms into and - out of the graph. The shown time depends on the graph you select. For example, you can zoom in a 30 days graph so that it shows data for 6 days.
  • x resets the graph to the default view.

In the upper right corner of every graph, you see three small icons:


You can do the following with them:

  • Zoom graph in new window : Opens a larger version of the graph in a new browser window.
  • Download the graph (PNG or SVG) : Shows a PNG or SVG file of the graph in a new browser window. You can then save or copy it for later use.

In every graph, you can also choose which specific channels (only on sensor pages) or indexes you want to see by using the corresponding check boxes or the Show all and Hide all buttons.

Note: Warning or error limits are only shown in graphs (highlighted in yellow or red) if you select exactly one channel with a limit.

Historic Data

The Historic Data tab is available for sensors only. Please see section Historic Data Reports .

Sensors Lists

Viewing lists of sensors is a great way to keep an eye on your network status because you can select which kind of sensors you would like to see. There are many different sensor list views available, such as a list of favorite sensors and top 10 lists, lists filtered by current sensor status, value, availability, tag or type, sensor cross reference, and many more.

Sensor lists are available from the main menu bar. Click the Sensors entry to show a table list of all sensors. In the table list appearing, you can re-sort the items by clicking on the column's header items (see section Working with Table Lists). Hover over it to show other menu options. For detailed information about the available options, please see Main Menu Structure (Sensors ) section.


The Alarms tab is not available for sensors, but for probes, groups, and devices only. Please see the Alarms section.

System Information

The System Information tab is available for devices only. Please see section System Information.


The Logs tab shows past activities and events regarding the currently selected object. Please see the Logs section.

Related Topics


Knowledge Base: How does PRTG compute CPU Index, Traffic Index and Response Time Index?


Ajax Web Interface—Basic Procedures—Topics

Other Ajax Web Interface Sections

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