Intel Corporation UNINETT We define Dynamic Host Configuration Protocol (DHCP) options being used by Preboot eXecution Environment (PXE) and Extensible Firmware Interface (EFI) clients to uniquely identify booting client machines and their pre-OS runtime environment so that the DHCP and/or PXE boot server can return the correct OS bootstrap image (or pre-boot application) name and server to the client. This memo provides information for the Internet community.