INSTALL AND CONFIGURATION NETWORK-MANAGER ON UBUNTU 16.10

Installation

NetworkManager should be installed by default on Ubuntu Desktop installs, as well as most flavours of Ubuntu.

To install NetworkManager:

sudo apt-get update
sudo apt-get upgrade

sudo apt-get install network-manager

Using Systemd

Systemd became the default initialization system in Ubuntu 15.04. Here's how to start Network Manager and enable it to be restarted after a reboot:

Start  network manager

sudo systemctl start NetworkManager.service

Enable restarting the network manager when the system reboots

sudo systemctl enable NetworkManager.service

Issues

If it is not managing your network connections, you'll need to comment out the references to all interfaces (except lo) in /etc/network/interfaces to let Network Manager handle them.

sudo cp /etc/network/interfaces /etc/network/interfaces.bak
sudo nano /etc/network/interfaces

It should look similar to this when you are done:

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# This is a list of hotpluggable network interfaces.
# They will be activated automatically by the hotplug subsystem.
# auto eth1

# iface eth1 inet dhcp

Then reboot and you should be good to go!

/etc/network/interfaces file:

 auto lo
 iface lo inet loopback

 /etc/NetworkManager/NetworkManager.conf file:

 [main]
 plugins=ifupdown,keyfile,ofono
 dns=dnsmasq

 [ifupdown]
 managed=true

If it is not managing your network connections, you'll need  do the following:

  sudo nmcli dev set enp8s0 managed yes


Try to the following (backup orig file, and create 0 bytes file instead)
  sudo mv /etc/NetworkManager/conf.d/10-globally-managed-devices.conf  /etc/NetworkManager/conf.d/10-globally-managed-devices.conf_orig

  sudo touch /etc/NetworkManager/conf.d/10-globally-managed-devices.conf  

Stopping and Disabling NetworkManager

The steps to disable NetworkManager depend on which of the initialization subsystems are running: Upstart or Systemd.

Using Systemd

Systemd became the default initialization system in Ubuntu 15.04. Here's how to stop and disable Network Manager without uninstalling it:

Stop network manager

sudo systemctl stop NetworkManager.service

Disable network manager (permanently) to avoid it restarting after a reboot

sudo systemctl disable NetworkManager.service

To list the currently available network connections, issue a command as follows:

To list the currently available network connections, issue a command as follows:

~]$ nmcli con show
NAME              UUID                                  TYPE            DEVICE
Auto Ethernet     9b7f2511-5432-40ae-b091-af2457dfd988  802-3-ethernet  --
ens3              fb157a65-ad32-47ed-858c-102a48e064a2  802-3-ethernet  ens3
MyWiFi            91451385-4eb8-4080-8b82-720aab8328dd  802-11-wireless wlan0

Note that the NAME field in the output always denotes the connection ID (name). It is not the interface name even though it might look the same. In the second connection shown above, ens3 in the NAME field is the connection ID given by the user to the profile applied to the interface ens3. In the last connection shown, the user has assigned the connection ID MyWiFi to the interface wlan0.

Adding an Ethernet connection means creating a configuration profile which is then assigned to a device. Before creating a new profile, review the available devices as follows:

~]$ nmcli dev status
DEVICE  TYPE      STATE         CONNECTION
ens3    ethernet  disconnected  --
ens9    ethernet  disconnected  --
lo      loopback  unmanaged     --

Adding a Static Ethernet Connection

To add an Ethernet connection with static IPv4 configuration, a command in the following format can be used:

nmcli connection add type ethernet con-name connection-name ifname interface-name ip4 address gw4 address

IPv6 address and gateway information can be added using the ip6 and gw6 options.

For example, a command to create a static Ethernet connection with only IPv4 address and gateway is as follows:

~]$ nmcli con add type ethernet con-name test-lab ifname ens9 ip4 10.10.10.10/24 \
gw4 10.10.10.254

Optionally, at the same time specify IPv6 address and gateway for the device as follows:

~]$ nmcli con add type ethernet con-name test-lab ifname ens9 ip4 10.10.10.10/24 \
gw4 10.10.10.254 ip6 abbe::cafe gw6 2001:db8::1
Connection 'test-lab' (05abfd5e-324e-4461-844e-8501ba704773) successfully added.

⁠Adding a Dynamic Ethernet Connection

To add an Ethernet configuration profile with dynamic IP configuration, allowing DHCP to assign the network configuration, a command in the following format can be used:

nmcli connection add type ethernet con-name connection-name ifname interface-name

For example, to create a dynamic connection profile named my-office, issue a command as follows:

~]$ nmcli con add type ethernet con-name my-office ifname ens3
Connection 'my-office' (fb157a65-ad32-47ed-858c-102a48e064a2) successfully added.