Comment 8 for bug 1246236

So in my case, the problem was PEBKAC and networking. Specifically I had two interfaces on my MAAS server that were connected to the same network, both had equally weighted routes to the gateway. Only one of them was configured in MAAS for the cluster controller. It was (seemingly) by chance that the second NIC was the one that the other nodes were trying to TFTP off of.