I have a device with 2 SFP+ interfaces sharing the same PCI address.
At boot time it is unclear which one gets initialized first and thus they may end up swapping their names at every reboot.
[ 24.691101] mlx4_core 0000:04:00.0 eth3: renamed from e5 [ 24.696799] mlx4_core 0000:04:00.0 eth4: renamed from e6
Sometimes eth3 and eth4 may come up with names inverted, thus messing up the configuration.
Problem witnessed on 1.4.
There should be some way to firmly identify them and be able to set a static name.