Preboot Execution Environment
RIS uses the new Preboot Execution Environment (PXE) extensions to DHCP to initiate the installation of an operating system from a remote source to a client's local hard disk.
The PXE environment is built on a foundation of Internet protocols and services that are widely used in the computer industry. These include TCP/IP, DHCP, and TFTP. The PXE extensions to the DHCP protocol allows for information to be sent to network-bootable systems and allow these systems to find RIS servers.