We need more details in order to help troubleshoot the problem. Is he connecting directly to the fixture with his Mac, or is he using a network switch/hub?
One thing to check which can cause problems is to make sure he has his wireless internet (airport) turned off. If this is turned on, he will not be able to connect to the DL.2s.
If he is connecting directly, he will need a cross-over ethernet cable. MACs do not have autoswitching network ports like most PC laptops do. Also, make sure the network is connected before turning the DL.2 on.
There is a bug currently that will cause the network connection not to function if the network is connected after the DL.2 has been booted. This will be fixed in our next release of software.
