Table of Contents
Disable Consistent Interface Device Naming
To regain the ethX back, edit the grub file.
vi /etc/default/grub
Look for GRUB_CMDLINE_LINUX and add or change to the following net.ifnames=0. FROM:
GRUB_CMDLINE_LINUX="crashkernel=auto resume=/dev/mapper/cl-swap rd.lvm.lv=cl/root rd.lvm.lv=cl/swap rhgb quiet"
TO:
GRUB_CMDLINE_LINUX="crashkernel=auto resume=/dev/mapper/cl-swap rd.lvm.lv=cl/root rd.lvm.lv=cl/swap net.ifnames=0 rhgb quiet"
[root@centos7-test1 ~]# ip addr show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 9000 qdisc pfifo_fast state UP group default qlen 1000
link/ether 02:00:17:00:b1:dc brd ff:ff:ff:ff:ff:ff
inet 10.0.0.2/24 brd 10.0.0.255 scope global dynamic ens3
valid_lft 86202sec preferred_lft 86202sec
inet6 fe80::17ff:fe00:b1dc/64 scope link
valid_lft forever preferred_lft forever
[root@centos7-test1 ~]# vi /etc/default/grub
[root@centos7-test1 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-1062.12.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1062.12.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-1062.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1062.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-229.1.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-229.1.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-64cb9cb13e6a425f9bca6c461e593eb3
Found initrd image: /boot/initramfs-0-rescue-64cb9cb13e6a425f9bca6c461e593eb3.img
Found linux image: /boot/vmlinuz-0-rescue-5eef1a77fa764e12a0a38a6c52d9818b
Found initrd image: /boot/initramfs-0-rescue-5eef1a77fa764e12a0a38a6c52d9818b.img
done
[root@centos7-test1 ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens3
# Generated by dracut initrd
NAME="ens3"
DEVICE="ens3"
ONBOOT=yes
NETBOOT=yes
UUID="673dfd0f-eece-41f6-b538-6233106248df"
IPV6INIT=yes
BOOTPROTO=dhcp
TYPE=Ethernet
NM_CONTROLLED=no
[root@centos7-test1 ~]# mv /etc/sysconfig/network-scripts/ifcfg-ens3 /etc/sysconfig/network-scripts/ifcfg-eth0
[root@centos7-test1 ~]# systemctl disable NetworkManager
[root@centos7-test1 ~]#
[root@centos7-test1 ~]#
Before reboot :
[root@centos7-test1 ~]# vi /etc/sysconfig/network-scripts/ifcfg-eth0
...... NAME=eth0 DEVICE=eth0 ......
Change ethernet name from ens3 to eth0.
rm '/etc/systemd/system/multi-user.target.wants/NetworkManager.service' rm '/etc/systemd/system/dbus-org.freedesktop.NetworkManager.service' rm '/etc/systemd/system/dbus-org.freedesktop.nm-dispatcher.service'
But still in next reboot it might change to earlier one, for this we have to make them persistent through editing it system file named /usr/lib/udev/rules.d/60-net.rules
[root@host1 ~]# cat /usr/lib/udev/rules.d/60-net.rules
ACTION=="add", SUBSYSTEM=="net", DRIVERS=="?*", ATTR{address}=="52:54:00:5f:d0:28", NAME="eth0"
Now we permanent rename Network Ethernet cards name to required one.
[root@WesternStar rules.d]# pwd
/etc/udev/rules.d
[root@WesternStar rules.d]# cat 70-persistent-net.rules |grep -v \#
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:4e:40:9a", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
[root@WesternStar rules.d]#[root@centos7-test1 ~]#reboot
Unmask NetworkManager Service
nmuti is the command to launch NetworkManager. In previous section, we have disabled and masked this serviec. Here is the step to unmask and enable it.
[root@centos7-test1 ~]# systemctl list-unit-files | grep Network NetworkManager-dispatcher.service disabled NetworkManager-wait-online.service masked NetworkManager.service masked [root@centos7-test1 ~]# systemctl unmask NetworkManager Removed symlink /etc/systemd/system/NetworkManager.service. [root@centos7-test1 ~]# systemctl start NetworkManager [root@centos7-test1 ~]# nmuti [root@centos7-test1 ~]# systemctl status NetworkManager
[root@centos7-docker-portainer ~]# systemctl unmask NetworkManager.service Removed symlink /etc/systemd/system/NetworkManager.service. [root@centos7-docker-portainer ~]# systemctl unmask NetworkManager-wait-online.service Removed symlink /etc/systemd/system/NetworkManager-wait-online.service.
