Issue

• In RHEL 7 system NIC naming has been changed to ethX style by adding net.ifnames=0 and biosdevname=0 to grub file. After doing that and rebooting the system when system boots up, MAC address mapping to NIC names are as eth0 - 8c:dc:d4:b7:xx:xx and eth1 - 8c:dc:d4:33:yy:yy
• Now the requiremet is NIC port whose MAC is 8c:dc:d4:b7:xx:xx should be named as eth1 and the NIC port whose MAC is 8c:dc:d4:33:yy:yy should be named as eth0.
• So to achieve that have tried adding HWADDR accordingly in the respective ifcfg-ethN files and then after reboot interfaces are coming up in the same way as that as that of original mapping.
• In logs can see below error at the time when udev tried renaming the interfaces:

Apr 20 05:32:38 HOSTNAME systemd-udevd: error changing net interface name eth0 to eth1: File exists
Apr 20 05:32:38 HOSTNAME systemd-udevd: error changing net interface name eth1 to eth0: File exists