I have 1800 nodes and I am trying to figure out if they are in SolarWinds. I need to know what is in and what is not.
Is there a way I can import this list and have SolarWinds return a report with a yes or no if it is in SolarWinds.
i would suggest that you export your SolarWinds inventory (create a generic report with just ALL nodes) to EXCEL and use EXCEL to compare. SolarWinds can not do what you ask natively.
I've always loved the power, flexibility and ease of Notepad++ for comparing.
So as per @dclick suggestion, export all your nodes and then paste them into a tab in Notepad++. Then do the same for your current known list (from a CMDB or similar) and then run the compare. plugin (which you will need to have also installed via the Plugins Admin).
I second using Notepad++. Alternatively there's also a great compare function in Visual Studio Code.