Creating Devices and Sensors Using the Auto-Discovery

PRTG's Auto-Discovery is a great way to automatically create a sophisticated and concise set of sensors for your complete network. It is mainly suitable for LAN discovery since it involves a lot of SNMP and WMI.

How it works

PRTG's Auto-Discovery process has three stages:

  • Step 1: Scanning a network segment for devices using PINGs (for groups only).
  • Step 2: Assessing the device type for all devices discovered in Step 1 (using SNMP, WMI and other protocols).
  • Step 3a: Creating sensor sets that match the discovered device types of Step 2 (based on built-in device templates with recommended sensors for many device types).
  • Step 3b (optional): Creating sensor sets using user created device templates (see Copying Devices by Cloning or Using Device Templates)

The Auto Discovery can be used on a group level for a range of IP addresses, or for individual devices you might have created manually. It can be run just once, on demand via the context menu, or scheduled every hour, day or week. Running the Auto Discovery every day or week will automatically create new sensors when new devices are connected to the network. As soon as new devices or sensors are discovered, new "ToDos" are created and mailed to the system admin.

Please be aware of the following restrictions of the Auto Discovery:

  • PRTG can not discover devices that can not be pinged, since Step 1 uses PINGs (e.g. if a firewall blocks echo requests, a device behind it cannot be discovered).
  • You must supply authentication settings for SNMP, Windows/WMI and VMware servers in order to fully exploit the power of this feature.
  • If a device has more than one IP address, it may show up more than once in the discovery results, even though PRTG tries to identify these situations.

Creating an Auto-Discovery Group

To create a new auto discovery group, go to the devices list ("Devices" in the main menu) and locate either a probe or group that is intended to contain the new group. Right click on the object and select "Add Auto-Discovery Group..." from the context menu.

Enter a name for the group (and optionally Tags) and choose the desired option for the "Sensor Management" setting:


You have three options:

  • Automatic Device Identification (Standard, recommended): This recommended option should work fine for most installations.
  • Automatic Device Identification (Detailed, may create many sensors): This option is only suitable for small network segments and whenever you want to monitor the maximum number of sensors available.
  • Automatic Sensor Creation using specific Device Template(s): Choose this option if you do not want automatic device identification and would rather select the device templates manually, e.g. if you want to use a device template that you have created yourself. You will see a list of device templates from which you can select one or more templates.

Afterwards, enter the IP Base (the first 3 bytes of the IP Range) and the first and last 4th byte of the IP address range. As soon as you click on "continue", PRTG will start the discovery process, visible in the sensor tree ("Devices" menu item of the main menu):


If you keep looking at this page, you will see more and more devices and sensors showing up in the list. The Auto-Discovery process takes between 10 and 50 seconds per IP address, depending on  configuration and network.

All sensors created by this process will start monitoring immediately and will notify failures as soon as they happen.

Creating an Auto-Discovery Device

Creating sensors for just one device using the Auto-Discovery function is quite similar to creating an Auto-Discovery Group. Go to the devices list ("Devices" in the main menu) and locate either a probe or group that is intended to contain the new device. Right click on the object and select "Add Device..." from the context menu.


Enter a name and IP address (or DNS name) for the device and choose one of the options for "Sensor Management" (described above).

As soon as you click "Continue" the device assessment will begin and create the sensors that suit the device.


Keywords: Group,device,Sensor,Automatic Sensor Creation,Auto Discovery