Restore standard naming of network interfaces on Red Hat enterprise linux 7

Disabling consistent network device naming

To disable The consistent network device naming feature and create your own manual ma,ing scheme ,for example eth0,internet0 or lan0. Follow the below steps so that all network device names will be eth followed by an integer.

• Log in as root, or as a user with superuser privileges.
• Edit the GRUB 2 general settings file.

1. Create a backup copy of the settings file.

   # cp /etc/default/grub /etc/default/grub.bak

2. Open /etc/default/grub with a text editor.
3. Add kernel boot arguments to the value of the GRUB_CMDLINE_LINUX variable.
   The arguments to add are biosdevname=0 and net.ifnames=0. Make sure the arguments are at the end and between the delimiter characters (").         .

   GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet net.ifnames=0 biosdevname=0"                                                                         

4. Save the file, and then close the text editor 

• Determine whether the host is configured for UEFI or legacy boot mode..

  # find /boot -maxdepth 1 -type d

• If the output includes /boot/efi, the host is configured for UEFI boot mode.
• If the output does not include /boot/efi, the host is configured for legacy boot mode.

• Recreate the GRUB 2 boot configuration file.

          For UEFI boot mode:

# grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg

          For legacy boot mode:

# grub2-mkconfig -o /boot/grub2/grub.cfg

Found linux image: /boot/vmlinuz-3.10.0-229.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-229.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-09377eb6cd424f3e802d04d64a5da531
Found initrd image: /boot/initramfs-0-rescue-09377eb6cd424f3e802d04d64a5da531.img
done

• Change network device configurations.

1. Change directory to /etc/sysconfig/network-scripts.

   # cd /etc/sysconfig/network-scripts

2. List the network device configuration files.

   # ls ifcfg-* | grep -v ifcfg-lo
   ifcfg-enp0s3
   ifcfg-enp0s8
   ifcfg-enp0s9
   

   The ifcfg-lo file is excluded because it does not need to be changed.
3. Rename and edit device files.
   For example, if you have a device file named ifcfg-eno16777736, use the mv command rename it to ifcfg-eth0, 

   # mv ifcfg-enp0s3 ifcfg-eth0 
   # mv ifcfg-enp0s8 ifcfg-eth1 
   # mv ifcfg-enp0s9 ifcfg-eth2

4. change the values of the NAME and DEVICE variables inside the file to eth0/1/2..

# vi ifcfg-eth0 
TYPE=Ethernet
BOOTPROTO=none
DEFROUTE=yes
IPV4_FAILURE_FATAL=no
IPV6INIT=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
IPV6_FAILURE_FATAL=no
NAME=enp0s3   ---> change to eth0
UUID=54828c5b-65be-42b1-8b4e-07627c67487f
DEVICE=enp0s3 ---> change to eth0
ONBOOT=yes
IPADDR=192.168.78.51
PREFIX=24
DNS1=192.168.78.51
DNS2=192.168.78.52
DOMAIN=evilcorp.com
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
IPV6_PRIVACY=no

• Reboot the host.
  You can confirme the configuration by runing network manager user interface (nmtui) or
  the following commands : 

  # nmcli dev
  DEVICE  TYPE      STATE      CONNECTION
  eth0    ethernet  connected  eth0
  eth1    ethernet  connected  eth1
  eth2    ethernet  connected  eth2
  lo      loopback  unmanaged  --
  
  # nmcli con 
  NAME  UUID                                  TYPE            DEVICE
  eth0  54828c5b-65be-42b1-8b4e-07627c67487f  802-3-ethernet  eth0
  eth2  04583597-c715-4ac5-954e-13dc748991a9  802-3-ethernet  eth2
  eth1  2418c04d-4291-48e6-95d1-3de63cd58d6a  802-3-ethernet  eth1