Another foray into IPAM reporting. This report shows all the subnets that are not getting scanned; in most cases, this is probably because scanning is disabled although it could be a firewall or ACL issue as well. This report provides the details on what subnets are not getting scanned, and the subnet settings that may be preventing status updates. We use this as a tool for periodic review.
There's probably a lot more information here than is strictly necessary, but I find it helpful.