Since I switched to a new mainboard, I constantly got annoyed by the "new ethernet naming convention". Apparently that is the mechanism causing my ethernet cards suddenly being named p3p*. It is not a big issue that it happens, but something is preventing consitent naming of my networking devices.
After minor kernel updates, suddenly p3p0 is named p3p1. Thanks to this blog post's comments I finally have the eth* names back.
Short summary of the post
Just make sure you add biosdevname=0 to your boot options, e.g. by modifying /etc/default/grub and running $ sudo update-grub.
I experienced this myself on Ubuntu 12.04 and 14.04, but apparently RedHat based distro's are also affected.