BUG in undionly.kpxe

[robinsmidsrod]

Have you tried using ipxe.pxe instead of undionly.kpxe? It could be a problem in your BIOS PXE implementation, which undionly.kpxe is using. If so, you should verify you're using the latest BIOS firmware on the machines. You should also try to go through the checklist at http://ipxe.org/dev/driver to ensure the driver you're using actually works consistently. The link tests can be a bit tricky to do on VMs.