The preboot execution environment (PXE) is an environment to boot computers using a network interface independently of available data storage devices or installed operating systems. These topics discuss the PXELINUX and gPXE methods of PXE booting the ESX installer.

PXE uses DHCP and Trivial File Transfer Protocol (TFTP) to boot an operating system (OS) over a network.

Network booting with PXE is similar to booting with a DVD, but it requires some network infrastructure and a machine with a PXE-capable network adapter. Most machines that are capable of running ESX have network adapters that are able to PXE boot. After the ESX installer is booted, it works like a DVD-based installation, except that you must specify the location of the ESX installation media (the contents of the ESX DVD).

A host first makes a DHCP request to configure its network adapter and then downloads and executes a kernel and support files. PXE booting the installer provides only the first step to installing ESX. To complete the installation, you must provide the contents of the ESX DVD either locally or on a networked server through HTTP/HTTPS, FTP, or NFS. (See Preparing to Install ESX.)