Setting up a PXE boot server

Remote Starter

Article from ADMIN 69/2022

By Andreas Stolzenberger

Set up a PXE server for BIOS and UEFI clients and use it to boot Linux or Windows.

The preboot execution environment (PXE) lets you boot computers and virtual machines over a network. In this article, I describe how to set up a PXE server, go into detail about the role of the Dnsmasq service, and describe how to make individual PXE configurations.

BIOS

When a computer, whether physical or virtual, is switched on, a number of programs are executed before the operating system even starts. What the mainframe world refers to as initial program load (IPL) is commonly known in the PC world as booting. Technically speaking, this means that the processor sets the program counter to memory cell 0 and then works its way forward in memory until it finds executable program code. On a regular PC, what the CPU encounters first is the Basic Input Output System (BIOS) or, to be more precise, multiple BIOSs, because every device that is plugged into a PC is allowed to mount its own BIOS in memory. This code then runs before the operating system and initializes the hardware.

In a desktop PC, the graphics card BIOS is extremely important; otherwise, the screen would stay blank. On servers, which can get by without a graphics card if need be, a redundant array of independent disks (RAID) or storage area network (SAN) controller might need to run its BIOS first so that the booting operating system can find a hard disk. As early as in the 1980s, an option was introduced to run the system boot over a local area network (LAN) with a BIOS on the network interface card (NIC). At that time, however, competing NIC manufacturers used proprietary boot code. It wasn't until 1998 that Intel introduced the PXE 2.0 specification, which has been used for all systems ever since.

PXE has evolved in the meantime. Strictly speaking, two different network boot processes are in use: PXE for PCs with BIOS and PXE for systems with (Unified) Extensible Firmware Interface (U)EFI (

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