Submit a ticketCall us

Quickly Address Software Vulnerabilities
Patch Manager is an intuitive patch management software which extends the capabilities of WSUS and SCCM to not only patch Windows® servers and workstations, and Microsoft® applications, but also other 3rd-party applications which are commonly exploited by hackers. Learn more about our patch management solution.


Home > Success Center > Network Performance Monitor (NPM) > Remove disappeared APs

Remove disappeared APs

Table of contents
Created by Con Finucane, last modified by Tiarnan Stacke on Jul 22, 2016

Views: 109 Votes: 6 Revisions: 6


Note: The following article applies to NPM 11.5.3 and earlier. If you wish to achieve this functionality in NPM 12 or newer please see the following article: Remove Disappeared APs in NPM 12 or later


By default Wireless Access Points that disappear are removed from the database. This means that they cannot be alerted on by Orion Alerts.

We can modify the configuration of Orion to change this behavior so that Access Points which disappear will be left in the Orion in an Unknown State.


Note: If the following configuration change is implemented APs will no longer be deleted from the database.


NPM versions 11.5.x, 11.0.x and 10.7​


Warning: SolarWinds strongly recommends that you create a backup of the following file:

C:\Program Files (x86)\SolarWinds\Orion\Wireless\SolarWinds.Wireless.Collector.dll.config

Modify the CONFIG file using a text editor:

  1. Find the following key:
    <add key="RemoveDisappearedAPs" value="True" />
  2. Change the key to the following:
    <add key="RemoveDisappearedAPs" value="False" />
  3. Save the changes.
  4. Restart Orion Services.



The functionality works in the following way:


<add key="RemoveDisappearedAPs" value="True" />

  •  When the AP disappears from the controller's SNMP it's removed from NPM.
  •  An AP which disappears cannot be alerted on as it gets removed from the Database.

<add key="RemoveDisappearedAPs" value="False" />

  • When an AP disappears from the WLC's SNMP the Access Point will go into an Unknown State in NPM.
  • If the AP appears on another WLC it will appear as a new Access Point.
  • When the AP comes back to the old WLC again, the once disappeared AP is marked as UP again.
  •  An alert can be triggered for when a AP goes into an Unknown State (Disappeared) and reset the alert when the AP reports in an Up status.




Last modified
04:18, 22 Jul 2016