Device not discovered OR Device not appearing OR Devices mapping together in N-able N-central OR Device disappeared from N-able N-central

Last Modified

Wed Aug 21 12:24 GMT 2019

Description

  • Device is not discovered, device is not appearing, devices are mapping together or device disappeared from N-able N-central.

Environment

  • N-able N-central

Solution

  • The N-able N-central logic is built to avoid proliferating duplicate devices into the managed view.
  • As such, N-able N-central will often map devices together based upon MAC address, IP, Hostname, or N-able N-central 's Asset Tag (or a combination of these).
  • The N-able N-central logic is to map devices together, rather than create a new one.
  • If Use Discovered Name is enabled, the new device may overwrite an old device name, causing the original to appear deleted or missing.
  • When a freshly installed device (by probe discovery, or manual install) doesn't appear within N-able N-central , it could be that similar MAC, partial MAC, IP or hostname could be causing the new device to check into a pre-existing appliance within N-able N-central .
  • If you're experiencing new device(s) are not found or old device(s) are missing in the N-able N-central UI, most likely what has happened is the device has been matched to a pre-existing device in N-able N-central.
  • This could be happening for any of the following reasons:
    • An identical/duplicate MAC address is matched to an existing device.
    • A device shares a combination of similar hostname, IP and/or partial MAC address.
    • A device is a cloned Windows Image or Cloned VM/Guest.
  • If this is caused by reason 1 from above, please review the following:
    • Devices may share an identical NIC/Bluetooth device/WAN card, especially if the hardware is interchanged, such as a shared USB WAN dongle.
    • Also, devices from the same vendor can have the same virtual device drivers which have the same MAC.
    • When a new device is registered to N-able N-central by probe discovery, or manual install, it doesn't appear within N-able N-central , or it overwrites a previously existing device within N-able N-central .
    • If this is happening for only a small number of devices, the fix is to manually create the appliance within N-able N-central , then install with Activation Key:
      1. Click Actions > Add/Import Devices.
      2. Under Manually Create a Device that Represents an External Website or IP Address, click Add Device.
      3. Enter the Name, Class, Network Address (internal IP/hostname) and Operating System information.
      4. Select Local Agent.
      5. Click Finish.
      6. On the new device, open N-able N-central in a browser.
      7. Get the Activation Key for the device under Settings > Local Agent.
      8. Download the Agent Installer.
      9. When prompted, paste the Activation Key from step 7 above.
      10. Complete the install.
      • If this is happening for many devices, you can resolve it with MAC address exclusions.
      • To permanently prevent mapping/overwriting due to duplicate MACs:
        1. Determine the common duplicate MAC address.
          • You can list the adapters in the device, for example, 'ipconfig /all' (Windows), 'ifconfig' or 'ip address sh' (Linux/MacOS).
        2. Go to Administration > Defaults > Discovery Defaults.
        3. Go to the MAC Addresses to Exclude section.
        4. Select Add New MAC Address.
        5. Enter in a description and new MAC address
        6. Click Save.
  • If this is caused by reason 2 from above, please review the following:
    • This could be because the customer does not have DNS scavenging enabled, or that the devices simply have some similar characteristics (hostname, IP and/or partial MAC address).
    • Since a match can occur on the IP address, it is strongly recommended to enable DHCP reservation if using DHCP at the site.
    • To resolve, please follow the steps from reason 1 above to create the device manually
  • If this is caused by reason 3 from above, please review the following:
    • From N-able N-central version 10.2 and above, a feature to further prevent duplicate devices was introduced.
    • This can also cause Windows devices to be mapped together if a Windows Image that already contains the N-able N-central Asset Tag, which was from a cloned device.
    • So, N-able N-central 's Asset Tag feature has already created a File, WMI entry & Registry entry before the Image was taken/device was cloned.
    • To resolve, please see the article below: