Grub Not Routing TFTP Appropriately

[Travis DePrato]

Hello, all!

I've been attempting to get UEFI Network booting working for a while now
(compounded by many unrelated issues) but I've run into one that I believe
to be definitely the fault of GRUB (perhaps this should be a bug report?
I'm not sure).

I've been using various grubx64.efi/bootx64.efi/core.efi images. Each
machine seems to have the same issue: the uefi network rom loads the grub
efi image appropriately, then when it tries to load grub.cfg (for
grubx64.efi) or the other components (starting with normal.mod), it routes
the packets incorrectly.

For the initial .efi image, it communicates directly with the TFTP server
on the ethernet layer (i.e. packets are routed directly to the mac address
of the TFTP server) whereas when grub continues trying to load components,
it tries to route through the router/gateway (it first arp's for the IP of
the gateway sends packets to the ethernet address of the gateway), and
those packets are summarily dropped (I've confirmed that the TFTP server
doesn't get them via wireshark).

Ideas?

Thanks!
Travis
-- 
Travis DePrato (he/him/his)
University of Michigan, Ann Arbor
Computer Science & Engineering
Mathematics (Discrete and Algorithmic Methods)
Computer Consultant at EECS DCO