EX6150v2 DHCP Reservation

Hi,

I have the D7000 and extend the network using an EX6150v2. My CCTV cameras connect to the extender and I then monitor from my PC and the TV in my lounge.

The challenge I face is the IP address on the cameras changes from time to time and when they do I can nolonger connect to them using my monitoring software until I reconfigure the software with the new IP's.

How do I set a DHCP reservation for the cameras? The D7000 takes care of DHCP but I can only reserve based on Mac address which the EX6150v2 transmits as a Virtual MAC Address so is the same for all connected devices.

Am I missing sonmething really obvious? :)