iPXE Chooses Wrong Nework Interface

[necouchman]

So, I'm using iPXE with some Dell servers that have on-board Broadcom interfaces. Each of these systems has two on-board 5708S interfaces, one of which is connected to a DHCP-enabled network that should allow PXE booting. This works fine with the built-in management firmware.

I've generated the iPXE image for these network cards, and successfully used the uxdiag utility (replacement for b57udiag) to burn the iPXE ROM to the MBA space on the network card (apparently with uxdiag, mba replaces all of the pxe commands). However, I'm running into a problem with the boot. The iPXE ROM is loading from the correct Ethernet interface (I can see this by verifying the PCI ID that it uses), but it is configuring the wrong interface. On this particular server, the second Broadcom interface is the one that is DHCP-enabled, but it seems like iPXE is choosing either the first MAC address or the first PCI ID that it sees - not really sure which one. So, IPXE starts from the correct PCI card, but tries to boot from the other interface.

Anyone ever run into this before? Any way to configure the iPXE firmware that I've just burned to make sure it activates the correct interface?

-Nick