You need a PXELINUX configuration file to boot the ESXi installer on a legacy BIOS system. The configuration file defines the menu displayed to the target ESXi host as it boots up and contacts the TFTP server for all SYSLINUX configurations, including PXELINUX and gPXELINUX.

This section gives general information about PXELINUX configuration files. For examples, see Sample DHCP Configurations.

For syntax details, see the SYSLINUX web site at

In the PXE configuration file, you must include paths to the following files:

mboot.c32 is the boot loader.

boot.cfg is the boot loader configuration file.

See About the boot.cfg File

For the file name of the PXE configuration file, select one of the following options:

01-mac_address_of_target_ESXi_host. For example, 01-23-45-67-89-0a-bc

The target ESXi host IP address in hexadecimal notation.


The initial boot file, pxelinux.0 or gpxelinux.0, tries to load a PXE configuration file in the following order:


It tries with the MAC address of the target ESXi host, prefixed with its ARP type code, which is 01 for Ethernet.


If that attempt fails, it tries with the hexadecimal notation of target ESXi system IP address.


Ultimately, it tries to load a file named default.

Save the file in /tftpboot/pxelinux.cfg/ on the TFTP server.

For example, you might save the file on the TFTP server at /tftpboot/pxelinux.cfg/01-00-21-5a-ce-40-f6. The MAC address of the network adapter on the target ESXi host is 00-21-5a-ce-40-f6.