Comment 15 for bug 1284043

I confirm that set the following to /etc/default/grub fixed the problem:
GRUB_CMDLINE_LINUX_DEFAULT="net.ifnames=1 biosdevname=0"
followed by
sudo update-grub
and setup the naming in
/etc/udev/rules.d/70-persistent-net.rules

Before:
# lshw -businfo -C network
Bus info Device Class Description
===================================================
pci@0000:03:00.0 em1 network NetXtreme II BCM5709 Gigabit Ethernet
pci@0000:03:00.1 em2 network NetXtreme II BCM5709 Gigabit Ethernet
pci@0000:04:00.0 em3 network NetXtreme II BCM5709 Gigabit Ethernet
pci@0000:04:00.1 rename5 network NetXtreme II BCM5709 Gigabit Ethernet

After:
# lshw -businfo -C network
Bus info Device Class Description
================================================
pci@0000:03:00.0 em1 network NetXtreme II BCM5709 Gigabit Ethernet
pci@0000:03:00.1 em2 network NetXtreme II BCM5709 Gigabit Ethernet
pci@0000:04:00.0 em3 network NetXtreme II BCM5709 Gigabit Ethernet
pci@0000:04:00.1 em4 network NetXtreme II BCM5709 Gigabit Ethernet

For those wondering about the change in interface naming:
http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames/