Years went by, pretty sure the wish list must have exploded by now
The question regarding IPAM capabilities popped up also in my company. We manage about 1000 subnets (industrial networks, so a lot of segmentation/segregation). So how can we keep track of all these mostly small (eg. /26, /27, /28) subnets?
We tried SolarWinds IPAM, but after some testing we said, let's think out of the box, so we used Lansweeper

.
Hence, I imported all our subnets under Asset Groups/IP Address Range Locations. Because we don't use the deployment feature (we have other tools for that), we inserted the subnet (CIDR notation) under Package Share en Subnet Responsible (contact) under Share Username.
Additionally, I've added for every subnet IP Range Scanning with the corresponding start IP address, and the Subnet Description under Scanning Targets. Of course, 'Save pinged IP' is activated.
Lastly, I've created a custom report that correlates all this information together:
Select Top 1000000 tsysIPLocations.IPLocation,
tsysIPLocations.PackageShare As Subnet,
tsysIPLocations.Realstart As StartIP,
tsysIPLocations.Realend As EndIP,
tsysIPLocations.ShareUsername As Contact,
Count(tblAssets.AssetID) As [used IP],
Case
When Right(tsysIPLocations.PackageShare, 2) = 24 Then 254
When Right(tsysIPLocations.PackageShare, 2) = 25 Then 126
When Right(tsysIPLocations.PackageShare, 2) = 26 Then 62
When Right(tsysIPLocations.PackageShare, 2) = 27 Then 30
When Right(tsysIPLocations.PackageShare, 2) = 28 Then 14
Else 6
End As [Max IPs],
tsysIPScanRanges.Description As [Subnet Description]
From tsysIPLocations
Left Join tblAssets On tsysIPLocations.LocationID = tblAssets.LocationID
Left Join tsysIPScanRanges On tsysIPLocations.Realstart =
tsysIPScanRanges.Ipstart
Where tsysIPLocations.Realstart Like '%10.99.%'
Group By tsysIPLocations.IPLocation,
tsysIPLocations.PackageShare,
tsysIPLocations.Realstart,
tsysIPLocations.Realend,
tsysIPLocations.ShareUsername,
tsysIPScanRanges.Description
Order By StartIP
IPLocation Subnet StartIP EndIP Contact usedIP Max IPs Subnet Description
AAN1-B520-19 10.99.137.224/28 10.99.137.225 10.99.137.238 Barry E 1 14 SA SERVER Network
AAN1-B520-40 10.99.136.0/26 10.99.136.1 10.99.136.62 Freddy J 7 62 PIMS Test Servers
AAN1-B520-39 10.99.131.0/26 10.99.131.1 10.99.131.62 Bico VDS 51 62 PIMS Production Servers
You can easily click on the subnet and query the underlying hosts.
In a next step, I'll be exporting this data to Power BI to get a visual representation of the usage of our subnets.