I had a similar issue...
I was able to create Sites & Subnets and have those associated automatically using the AD import rules. However, I could not cretae Locations, which is the same as our Sites in AD.
Using the COnnector Solution I was able to create a data source from AD, and import Sites as Locations as well as automically associate Subnets to the Locations, much the same way the AD connector works.
Once that was completed I could then run the Location to Subnet Association and my Assets were automatically assigned to the proper Location based on their IP address.
This saved me from ahving to map subnets to locations by hand and everything runs on schedule so its all updated daily.