PXE booting over IPv6

[Michael Mohr]

Good afternoon;

I'm attempting to set up an IPv6-based PXE boot environment with iPXE and GRUB.  I've updated the option ROM on an Intel network card using the latest iPXE code (git rev 7fe0735) with IPv6 support enabled.  Booting from this card, iPXE is able to auto-configure both a link-local IPv6 address as well as one from radvd (via SLAAC).  iPXE also successfully requests additional parameters from a DHCPv6 server, including the bootfile-url, which allows it to retrieve a copy of GRUB generated as follows:

address@hidden:~$ grub-mkimage --version
grub-mkimage (GRUB) 2.02~beta2-9
address@hidden:~$ grub-mkimage --format=i386-pc-pxe --output=grub.pxe --prefix='(pxe)/boot/grub' \
> pxe tftp http cpuid echo gfxterm gzio minicmd normal png vbe

iPXE successfully downloads the GRUB PXE image from a local HTTP server and transfers control to it.  I am then dropped into a GRUB shell and the boot process stops.  I've tried running "net_ipv6_autoconf", which initially reports "error: couldn't autoconfigure PXE", but if I run it a few times it is eventually able to configure the network interfaces (as shown by "net_ls_addr") with appropriate IPv6 addresses.

Clearly GRUB isn't able to retrieve its configuration file for some reason.  I've placed one on the HTTP server specified in DHCP as http://[ipv6::address]/boot/grub/grub.conf and am able to retrieve it with a standard web browser.  I suspect that I'm missing something fundamental here, so any enlightenment you can provide is appreciated.

Thank you for your assistance.

-- 
Michael Mohr
Software Engineer III
Hyve Solutions