Network booting, shortened netboot, is the process of
booting a
computer from a
network rather than a local drive. This method of booting can be used by
routers,
diskless workstations and centrally managed computers (
thin clients) such as public computers at
libraries and schools.
Network booting can be used to centralize management of disk storage, which supporters claim can result in reduced capital and maintenance costs. It can also be used in
cluster computing, in which
nodes may not have local disks.
In the late 1980s/early 1990s, network boot was used to save the expense of a disk drive, because a decently sized harddisk would still cost thousands of dollars, often equaling the price of the
CPU
A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...
.
Hardware support
Contemporary
desktop personal computers generally provide an option to boot from the network in their
BIOS/
UEFI via the
Preboot Execution Environment (PXE). Post-1998
PowerPC (
G3 G5)
Mac systems can also boot from their
New World ROM firmware to a network disk via
NetBoot.
Old personal computers without network boot firmware support can utilize a
floppy disk
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined ...
or
flash drive containing software to boot from the network.
Process
The initial software to be run is loaded from a
server on the network; for
IP networks this is usually done using the
Trivial File Transfer Protocol (TFTP). The server from which to load the initial software is usually found by broadcasting a
Bootstrap Protocol
The Bootstrap Protocol (BOOTP) is a computer networking protocol used in
Internet Protocol networks to automatically assign an IP address to network devices from a configuration server. The BOOTP was originally defined in RFC 951.
While some part ...
or
Dynamic Host Configuration Protocol (DHCP) request.
Typically, this initial software is not a full image of the operating system to be loaded, but a small network boot manager program such as
PXELINUX which can deploy a boot option menu and then load the full image by invoking the corresponding second-stage
bootloader.
Installations
Netbooting is also used for unattended operating system installations. In this case, a network-booted ''helper operating system'' is used as a platform to execute the script-driven, unattended installation of the intended operating system on the target machine. Implementations of this for
Mac OS X and
Windows
Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for ...
exist as
NetInstall
NetBoot was a technology from Apple which enabled Macs with capable firmware (i.e. New World ROM) to boot from a network, rather than a local hard disk or optical disc drive. NetBoot is a derived work from the Bootstrap Protocol (BOOTP), and is ...
and
Windows Deployment Services, respectively.
Legacy
Before IP became the primary
Layer 3 protocol,
Novell
Novell, Inc. was an American software and services company headquartered in Provo, Utah, that existed from 1980 until 2014. Its most significant product was the multi- platform network operating system known as Novell NetWare.
Under the l ...
's
NetWare Core Protocol (NCP) and
IBM's
Remote Initial Program Load (RIPL) were widely used for network booting. Their
client implementations also fit into smaller
ROM than PXE. Technically network booting can be implemented over any of
file transfer or
resource sharing protocols, for example,
NFS is preferred by
BSD variants.
See also
*
Wake-on-LAN (WoL)
References
External links
PXE specificationThe Preboot Execution Environment specification v2.1 published by Intel & SystemSoft
Remote Boot Protocol Draftdraft of the PXE Client/Server Protocol included in the PXE specification
NetBootNetBoot 2.0: Boot Server Discovery Protocol (BSDP)
{{Firmware and booting