Firstly, to provide a little more context, Lansweeper uses a combination of the NetBIOS computer and domain name to form the unique identifier used for Windows computers. The NetBIOS computer name is also used to generate the asset name. Lansweeper retrieves NetBIOS information through the following methods:
- Unauthenticated (works even if no valid credentials are found): If TCP port 135 is open, NetBIOS information is attempted to be retrieved over TCP/IP via ports 139 and 445. A UDP check on port 137 is also tried.
- Authenticated: When port 135 is open and a scanning credential that can connect to WMI on the target computer is found, NetBIOS information is retrieved directly from the computer itself out of Win32_ComputerSystem (WMI).
If both methods above fail, but port 135 could be connected to, this will result in an Unknown asset. An Unknown asset indicates that the scanning service assumes it's a Windows computer but could not retrieve NetBIOS information to generate a full-fledged Windows computer asset.
To reduce the number of Unknown Assets in your Lansweeper setup, consider the following strategies:
1. Check Network Access: Ensure that Lansweeper can access all network segments. Confirm that firewalls and security settings permit Lansweeper to scan devices.
2. Update Credentials: Verify that all scanning credentials (Windows, SNMP, SSH, etc.) are current and have the necessary permissions to gather information from devices.
3. Utilize Active Scanning: Implement Active Scanning methods such as IP Range Scanning and Active Directory Scanning to ensure comprehensive device discovery.
4. Schedule Regular Scans: Set up regular scans to keep Lansweeper updated with network changes and newly added devices.
5. Use Correct Protocols: Ensure you use the appropriate scanning protocols for different device types. For instance, SNMP can be employed for network equipment, and SSH can be employed for Linux systems.
6. Review Scan Errors: Examine scanning errors and logs in Lansweeper to identify and resolve issues preventing asset identification.
7. Database Maintenance: Clean up the Lansweeper database to remove outdated or duplicate entries.
By implementing these steps, you should see a reduction in Unknown Assets.
Further investigation into specific scan settings may be required for persistent issues, and consulting the Lansweeper knowledgebase can provide additional solutions.
