This function will scan all the IP address ranges defined in the forest and display any IP address ranges that overlap another IP address range. Back in early days of AD overlapping subnets was considered bad, but now it's a common practice to define a catch all IP address range and assign it to the site that contains the default domain controllers, then define more precise or small IP address range to sites to controls which domain controllers are used for authentication.

When the test is run the output will display all the IP address ranges that are overlapping and to which sites that they are assigned, if the overlaps are for different sites, a yellow indicator is shown, if the overlaps are for the same site, then a green indicator is displayed.  The lights are not design to represent good or bad configuration, but just to make it easier to spot where IP address ranges are assigned to different sites.