This is under construction. I do not use CentOS as much as Ubuntu.
I've seen warnings from Red Hat saying the legacy network service and "network-scripts" package is deprecated and will be removed in a future release, so some of the old guides may not work in the future.
I am still using NetworkManager, but I at least get my legacy "eth0" naming back.
1) update the /etc/default/grub file, and add net.ifnames=0 biosdevname=0 to the GRUB_CMDLINE_LINUX line.
Your line may look something like this:
GRUB_CMDLINE_LINUX="crashkernel=auto rhgb quiet net.ifnames=0 biosdevname=0"
2) run "grub2-mkconfig" to rebuild your grub configuration.
3) Create your /etc/sysconfig/network-scripts/ifcfg-eth0 file. For example:
# # /etc/sysconfig/network-scripts/ifcfg-eth0 # # enable on boot ONBOOT=yes TYPE=Ethernet NAME=eth0 DEVICE=eth0 # ip configuration IPADDR=192.168.1.10 PREFIX=24 GATEWAY=192.168.1.254 # dns servers DNS1=22.214.171.124 DNS2=126.96.36.199 # search domains DOMAIN="localhost localhost.example.com"