Hello,
i'm having a very strange issue, i had installed a second DP in my environment, all looked to work fine, but now my clients using PXE boot refer to that new server when doing PXE boot, even if my DHCP is setup to refer to my first server (with option 66).
i tried to uninstall the second DP, it lead to another behavior, client keep stuck on DHCP discovery during boot. I have to disconnect the new DP to see things working normally.
I'm using windows server 2012 R2 and SCCM 2012 R2.