First Check if NetworkManager is running on Ubuntu / Debian

Usually you should be using NetworkManager by default (Ubuntu 14.04), just in case you want to be sure, use this command to verify:

dpkg --get-selections | grep network-manager

In case there is some output like:

network-manager install

it is installed, if there is nothing returned, you are probably using a different network managing daemon. It would be possible that network manager is installed but inactive. Lets check if its running the hard way:

ps aux | grep network-manager

If thats returning something different than itself, you can be sure using the NetworkManager in Ubuntu / Debian.

Disable Network Manager Completely

Here is how to disable Network Manager completely, so that Network Manager stops running on your Linux system.

To disable Network Manager on Debian 8 or later:

$ sudo systemctl stop NetworkManager.service
$ sudo systemctl disable NetworkManager.service

To disable Network Manager on Debian 7 or earlier:

$ sudo /etc/init.d/network-manager stop
$ sudo update-rc.d network-manager remove

To disable Network Manager on Ubuntu or Linux Mint:

$ sudo stop network-manager
$ echo "manual" | sudo tee /etc/init/network-manager.override

After disabling Network Manager on Debian or Ubuntu, use /etc/network/interfaces to configure network interfaces.

To disable Network Manager on Fedora or CentOS/RHEL 7 or later:

$ sudo systemctl stop NetworkManager.service
$ sudo systemctl disable NetworkManager.service

To disable Network Manager on CentOS/RHEL 6 or earlier:

$ sudo service NetworkManager stop
$ sudo chkconfig NetworkManager off

After disabling Network Manager on Fedora or CentOS, use /etc/sysconfig/network-scripts/ifcfg-ethX files to configure network interfaces.

Disable Network Manager for a Particular Network Interface on Debian, Ubuntu or Linux Mint
To disable Network Manager only for eth1 on Debian, Ubuntu or Linux Mint, you can do the following.

First, open the Network Manager configuration file in /etc/NetworkManager with a text editor, and set “managed=false”, typically shown under [ifupdown].

$ sudo vi /etc/NetworkManager/NetworkManager.conf
[ifupdown]
managed=false

Then in /etc/network/interfaces, add information about the interface you want to disable Network Manager for. In this example, the interface is eth1, and we are using static IP configuration.

$ sudo vi /etc/network/interfaces
# The loopback network interface
auto lo
iface lo inet loopback

# network interface not managed by Network Manager
allow-hotplug eth1
iface eth1 inet static
address 10.0.0.10
netmask 255.255.255.0
gateway 10.0.0.1
dns-nameservers 8.8.8.8

Then Network Manager automatically ignore any interfaces specified in /etc/network/interfaces, and stop managing them.

After rebooting, verify that Network Manager is successfully disabled for eth1.

$ nmcli dev status

Disable Network Manager for a Particular Network Interface on Fedora or CentOS/RHEL
The following steps will disable Network Manager for eth1 on Fedora, CentOS or RHEL.

Create an interface configuration file for eth1 (if not exist), and add “NM_CONTROLLED=no”.

TYPE="Ethernet"
NAME="eth1"
BOOTPROTO="static"
IPADDR=10.0.0.10
NETMASK=255.255.255.0
GATEWAY=10.0.0.1
HWADDR="00:90:29:95:EA:57"
ONBOOT="yes"
DEFROUTE="yes"
NM_CONTROLLED=no

Now enable network service so that eth1 is activated by network service automatically upon boot.

On Fedora or CentOS/RHEL 7 or later:

$ sudo systemctl enable network.service

On CentOS/RHEL 6 or earlier:

$ sudo chkconfig network on

Upon rebooting, verify that Network Manager is successfully disabled for eth1 with nmcli command.

$ nmcli dev status

Src: http://xmodulo.com/disable-network-manager-linux.html