I understand the boot process does a bunch of handshakes with the DHCP/PXE server, but after it loads into the WinPE environment, how does it know to grab the image file? Is there intelligence in the pxe boot file that tells it to grab it locally?
http://blogs.technet.com/b/dominikheinz/archive/2011/03/18/sccm-pxe-network-boot-process.aspx