Hi All,

  I just install SCCM 2012 R2 and deploy the OS to VM and Physical PC.  i was using MDT 2012 and noticed these two

 1. Do i have to add MAC address before deploy? ( MDT Doesn't)

 2. Do i have to press F12 or can this automate? 

As

1. If you deploy to All Unknown computers, you don't need to add the MAC address first;
2. Yes, you can automate that by using a Required deployment and making sure that the network device is the first boot device (personally I wouldn't do that to prevent potential issues).

#1: no - if you are using unknown computer support

#2: only if the deployment is 'available'. 'Required' ones do not prompt.