Once you have the TFTP server configured, the next step is to configure the DHCP server with scope options 66 and 67. You will need access to the DHCP server that is available on the same subnet as the ESXi's management network.
Configuring the DHCP server for a PXE boot
Getting ready
Before you begin, you will need to install and configure a TFTP server for PXE booting ESXi hosts. Read the Configuring the Trivial File Transfer
Protocol (TFTP) server for an ESXi PXE boot environment recipe. Also, make a note of the BIOS DHCP file name from the Auto Deploy Runtime Summary. As of vCenter 6.7, it is undionly.kpxe.vmware-hardwired.