LEM Non Domain Member Question

Check out the "DHCP but no Agent" and similar rules. The "DHCP but no Agent" rule looks for a DHCP lease where there's no LEM agent installed. You could also hook up your Active Directory groups, put all your known computer accounts in it, and modify the rule to look for a DHCP lease to a computer that's not in your group (e.g. replace the right hand side of the DHCP but no Agent comparison with your Domain Computers Group instead of All Installed Agents). You'll want to make sure that the DNS server the LEM appliance is configured for can resolve all those computer names to IPs, though, since the comparison needs to be able to compare computer name to IP (DHCP server only knows IP most reliably).  If you have different pools for domain and non-domain systems (or different networks/APs/etc) you could also build a rule that looks for an assignment in that pool. Or, if you really do have LEM agents installed everywhere, you can actually use the original rule.

Make sure you've got the LEM agent installed and DHCP connector configured on all of your DHCP servers, too, if you've got more than one. It's hard to know which server will pick up the DHCP request.