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 ESXi 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 ESXi have network adapters that are able to PXE boot. After the ESXi installer is booted, it works like a DVD-based installation, except that you must specify the location of the ESXi installation media (the contents of the ESXi 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 ESXi. To complete the installation, you must provide the contents of the ESXi DVD either locally or on a networked server through HTTP/HTTPS, FTP, or NFS. (See Preparing to Install ESXi.)