I have a working ConfigMgr 2012 R2 CU1 environment, with all servers on 2012 R2. After following the guide, I am still having trouble pxe booting. After the 'Downloading NBP file...' message, a 'Succeed to download NBP file.' message very briefly appears, followed by moving onto an ipv6 pxe attempt. I did have one successful pxe boot yesterday, but am unsure of what I changed that now prevents this from working. Any ideas? Thanks!