I have nodes that are discovered but details for typical node have all zeros (00:00:00:00:00:00) for MAC addresses. I do I am not sure if it has something to do with the upgrade of code on my Extreme XOS switches. Currently running 32.6.2.68 of the XOS code. the switch has SMNP3 enabled and system authenticates with it so I can't see why FDB not populating the MAC and even the IP ARP. What are the mechanisms that it uses to determine the MAC address of an endnode?