In order for Spectrum to associated a mac address to a Pingable model, the following two criteria must be met:
1. The "ARP Tables for Pingables" must be selected in the "Protocol Options" in the "Modeling Configuration" of the AutoDiscovery configuration:
2. A layer 3 device in the same subnet as the Pingable model must be modeled in the Spectrum database
When the "ARP Tables for Pingables" modeling protocol is selected, Spectrum looks for a layer 3 model that is in the same subnet as the Pingable model. If found, Spectrum reads the ipNetToMediaTable from the device to resolve a mac address to the ip address of the Pingable model. If resolved, the MAC_Address attribute id 0x110df on the Pingable model will be populated.