How can see ALL devices (including ethernet) connected to Airport Extreme? I am running Airport Utility 6.3.  I can see the list of WIRELESS clients connected.  I can't see anywhere in the utility where I can see WIRED/ETHERNET clients connected.

Other posts on this site refer to an Advanced Settings Tab on Airport Utility 6.x. or else Manual Setup.   I don't see this anywhere in the GUI.  Under the Network tab, you can reserve static IPs, but that's not what I want, I want to see which WIRED (not just wireless) devices are actually connected.  I'm trying to troubleshoot an issue with my DirecTV box which doesn't seem to be connecting even though I have reserved an IP for its MAC address.  Yes, I can ping the IP, but the point is if I want to set it to DHCP, I wouldn't know the IP, and it would be nice to just see what all the devices are.
There's a great shell command that scans your network on all interfaces that are connected. 

The command is arp -a.