Updated December 14, 2016
This article pertains to an issue that can happen where IPs that are not in use are being flagged as Used when a Neighbor Scan on the subnet finds an IP entry in the ARP cache of the scanned device that has an empty MAC or
IPAM versions 4.3.1 or earlier
This issue is caused when IPAM mistakenly takes the empty MAC as a true MAC and considering the IP entry in the cache to be in use.
Program Files (x86)\SolarWinds\Orion\IPAM.
<add key="NeigborScanJob.SkipEmptyMAC" value="False" />