Ever had to replace hardware in a linux box and then the networking wanted to screw with you? as in not find your NIC but lspci would list the NIC?
Yeah, this is the file is causing that issue. It records the MAC address of your NIC and then if it changes, it will rename your primary NIC as eth1. Also, if your new NIC name(eth1) isn't in your /etc/network/interfaces, you won't have any networking.
rm -rf /etc/udev/rules.d/*-persistent-net.rules
once you have ran this command, reboot and your should be good to go.