This bug made a lots of pain for me, but I've found workaround.
As cloudbuilders told option "netcfg/choose_interface=auto" still not working, and unfortunately BOOTIF=01-${mac-with-hyphens} is not working too.
There is undocumented feature in netcfg package. Option "netcfg/choose_interface" accepts raw MAC-address of nic to set up, so I passed to kernel cmdline option "netcfg/choose_interface=${netX/mac}" (${netX/mac} is variable in iPXE) and all works fine.
I don't know is it possible in PXELINUX, but it is easy in iPXE.
This bug made a lots of pain for me, but I've found workaround. choose_ interface= auto" still not working, and unfortunately BOOTIF= 01-${mac- with-hyphens} is not working too.
As cloudbuilders told option "netcfg/
There is undocumented feature in netcfg package. Option "netcfg/ choose_ interface" accepts raw MAC-address of nic to set up, so I passed to kernel cmdline option "netcfg/ choose_ interface= ${netX/ mac}" (${netX/mac} is variable in iPXE) and all works fine.
I don't know is it possible in PXELINUX, but it is easy in iPXE.