Basic Definitions for Upcoming PXE Projects - PXE, DHCP,NBP, TFTP, NFS

These are just basic definitions of what you need to know before you start on a PXE project. There are countless other resources with more detail if you are so inclined. This is just a primer.

• PXE (pronounced pixie)– Preboot Execution Environment: Allows computers and other devices to boot operating systems across network connections, and without having any directly attached storage. Surprisingly the newest version of the PXE specification, V2.1, September 20, 1999, isn't very new. (I guess that if it works would they fool with it.)
• DHCP – Dynamic Host Configuration Protocol: Briefly, DHCP assigns IP addresses and gateway information to client machines. The full definition is really beyond the scope of what we are doing here. Respectfully, if you don't know about basic DHCP functionality, you need to study up a bit before digging into PXE.
  PXE Specific: You need a DHCP server that will provide the extra PXE specific information including IP address of the TFTP boot server address and the file path to an NBP. Note: Your DHCP server built into your DSL or Wireless router will almost certainly NOT work for this project. Most home routers are incapable of being configured with the additional options required by PXE.
• NBP – Network Bootstrap Program: This is the OS boot loader with networking built in. This is transferred to the client via TFTP. After the NBP is loaded it must take over all network duties from the PXE enabled BIOS. The format of the NBP file is OS dependent and outside the spec for PXE. Once it loads, the actual PXE process is over.
• TFTP – Trivial File Transfer Protocol: It's just like FTP but less! TFTP will transfer files, but there is no user authentication and no flow control. It listens on UDP port 69 to handshake and assigns ports dynamically to transfer data. It's one of the slowest file transfer protocols there are even over fast networks, but it's only being used to get your initial boot files to your client.
• NFS – Network File System: This is an older but still widely used file remote file system protocol originally developed by Sun Microsystems. It is much faster than TFTP at data transfer. With the exception of the latest version 4 of NFS, it is a very unsecure protocol. (I never allow this traffic to cross a firewall on my networks.) In this case we are only using it to mount a read only file system containing only the read only Knoppix ISO file from CD so security isn't a huge problem. NFS uses several different daemons and its full configuration is beyond the scope of our work on this project. We are using NFS because that is what the Knoppix NBP uses. NFS is not part of the PXE specification.