- 18 Jul 2023
- 2 Minutes to read
- Updated on 18 Jul 2023
- 2 Minutes to read
Netreo periodically scans your network for the addition of new devices (roughly every hour). Any new devices discovered during a scan that respond to SNMP or WMI and are not currently managed by Netreo will be automatically added as a managed device and have a discovery poll run on them. The range of time during which Netreo performs its scans are controlled on the Auto Discover Schedule page. By default, Netreo is scheduled to scan for new devices 24 hours per day, every day. However, this schedule can easily be changed by an administrator.
Any subnet that is part of an RFC-1918 private address range (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16) with a subnet mask of /22 (255.255.252.0) or longer will be automatically enabled for autodiscovery scanning. Larger subnets (or those with public addresses) will need to be manually enabled before Netreo will scan them. To prevent Netreo from attempting to scan the Internet, the subnet scanner won't attempt to scan any subnets larger than class B.
Netreo runs its subnet scanner to look for new devices roughly every hour, within the scheduled autodiscovery times. As it discovers devices that are candidates to be monitored, it test communicates with these devices (via SNMP and Windows networking) using all of the credentials provided in the Device Discovery Wizard and any device templates that contain them, in the order in which they are provided. If any of the credentials work for a given device, and Netreo can identify that device as a type of device that is manageable, the device is added to Netreo and automatically configured (using auto-configuration rules and device templates).
If Netreo is not able to successfully authenticate with a device, that device is not added to Netreo. Devices that are not added wait in a queue to be rechecked every 5 minutes. If credentials become available that work, any applicable devices are then added to Netreo as above. (Devices running non-server operating systems will not be automatically added to Netreo. These kinds of devices may be added to Netreo manually, if desired, by using the device addition Manual Add tab. See Manually Add Devices to Netreo.)
Any devices that Netreo is able to successfully discover and begin monitoring have an action group named “Default Email Alerts” added to their host alert contacts list. This group is configured with the contact information provided in the “Default Host Alert Contact” section of the Device Discovery Wizard. This allows the provided contact to be alerted by email in the case of host failures, even if no other action groups are configured.
If you did not configure a default contact in the Device Discovery Wizard, downed-host alerts will not be sent unless you explicitly configure them for each device.
You can also provide Netreo with the IP address and credentials for a hypervisor server from which to discover your virtual environment. The current options allow you to select from either a vCenter or Hyper-V hypervisor type. Netreo uses the provided server to discover virtual hosts, guests and datastores which it can then automatically configure and monitor. Hypervisors can be added in the Device Discovery Wizard or on the Virtualization Administration page.