1. Download the iSCSI boot image BootIMG.FLB at this link https://www.supermicro.com/wdl/CDR-NIC_1.22_for_Add-on_NIC_Cards/Intel/LAN/APPS/BootUtil/ and download the DOS utility BootUtil.exe to flash it here https://www.supermicro.com/wdl/CDR-NIC_1.22_for_Add-on_NIC_Cards/Intel/LAN/APPS/BootUtil/DOS/
2. Copy both files into a bootable USB key and boot into DOS
3. run "Bootutil" to show the available NIC
4. run "bootutil -nic="NIC#" -up=iscsi -file=bootimg.flb"
example: Assume the desired NIC number is 1, then run "bootutil -nic=1 -up=iscsi -file=bootimg.flb"