@ntalbert If your fog server, dhcp server and pxe booting client are on the same subnet please try to do this: https://forums.fogproject.org/topic/9673/when-dhcp-pxe-booting-process-goes-bad-and-you-have-no-clue
I suspect you have a second dhcp server or proxy dhcp server on your network issuing IP addresses. Upload the pcap file to a google drive and post the link here or IM either Sebastian or myself and we will take a look at it.
The confusing bit is that according to the picture iPXE is getting to the target computer some how, and then getting the wrong IP address when it requeries for the next server. As well as why is it using tftp to get default.ipxe? At this point it should be using http. Are you trying to boot a virtual box vm in the pictures? Virtual box uses iPXE as its boot roms. One last bit, I’ve seen many home routers send its IP address out as a next server for some reason and the ip address of 192.168.1.1 makes me thing someone might have plugged in a home internet router into your network as a rouge device.