First, some background on Razor:
Take the time to read those over, install it, work with it a bit in VMs or so, as this takes off with the assumption that you already have a working Razor installation.
1) Rebuilding the razor.ipxe file:
razor config ipxe > /var/lib/tftpboot/razor.ipxe
2) Alternative DNSMASQ for chain booting certain NIC cards (similar to this):
3) A few spots to edit if you are running the Razor TFTP/PXE network on a different interface than your primary:
In /opt/razor/conf/razor_server.conf change the following lines:
Then, in /var/lib/tftpboot/razor.ipxe, change the following line: