The process of
booting a computer using a
network as opposed to reading information off the local
disk. On
TCP/IP networks this is traditionally achieved by the computer initially sending out a
bootp or
dhcp query. This query is received by the
server, which looks at the
MAC address of the packet, looks this up in its configuration file and then sends back a reply containing the
IP address that the machine should use along with some extra information. One of these pieces of information is a
filename (and possibly the IP address of a different server) which is then
TFTPed by the client. This code is then executed - it's usually a
kernel image of some description. Once the kernel has started, a second
bootp or
dhcp request is made. This time the OS configures the
network card and looks at the reply to see if it's given the location of an
NFS filesystem. If so, this is mounted as the root filesystem and the
OS is read off it.
Netbooting is common for diskless network workstations and X terminals. It's rarely used for larger workstations, simply because local disk is almost always much faster than the network.
See: