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 bootstrap an operating system (OS) over a network.

Network booting with PXE is quite similar to booting with a DVD, but 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. Once the ESX installer is booted, it works like a DVD-based installation, except that the location of the ESX installation media (the contents of the ESX DVD) must be specified.

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 Location of the ESX Installation Media.)