Use TCP, UDP, or other to communicate with UUT using MAC address instead of IP address

Question

I want to verify that the Ethernet port on my UUT works. 
My plan was to ping the UUT and verify that I got a response.  However, the UUTs will come to test with an IP that I cannot use on the network.  [Please don't ask me to explain why -- the IT group has their rules, and rules are rules after all . . . ] 
I can query the UUT (via the serial port) for it's MAC address.  But I cannot find any LabView VIs, or DOS executables which use the MAC address as a parameter to invoke a response from the device.
Does anybody have an idea of how I can verify the UUT Ethernet port without having to divorce myself from the company network and set up my own private network?  [Oh and by the way, before somebody suggests it, the IT group won't let me put a 2nd network card in my PC -- rules are rules after all . . . .]

Answer 1

I wouldn't worry too much about the address shown in the Remote Management tab.  The ARDAgent process, which is what is listening on his computer for connections from Remote Desktop, binds to all active network interfaces and ultimately that's all that matters. Of out curiosity though, to what IP address does the "unknown-b8-8d-##-##-##-##.home" dns name resolve?  Is it the WAN address?  I can't imagine it resolves to a private address like a 192.168.
In any event, let's focus back on the network structure. Does the BT router have both a hard wired LAN ethernet port as well as a WiFi radio for LAN connections?  My guess is yes. I am also assuming that he does *not* have another router attached to the BT LAN ethernet port like an Airport basestation that is serving the WiFi connections.  Typically, the LAN ethernet port is given, via DHCP, a real Internet accessible address but the addresses served via DHCP for wireless clients are private network addresses only.  It's seems unlikely to me that the router is automatically forwarding incoming connections to a private network address on the WiFi network.  But if he plugs his Mac in to the ethenert LAN port on the BT router then you should be able to connect directly to the address given to it via DHCP because it *should* be a real Internet accessible address.