how do you automatically enable network interface at system startup?

Question

I have a network interface that is configured for static ip address.

When I reboot I have to always open the NetworkManager GUI and click "connect" button.

How do you automatically enable network interface at system startup?

Answer 1

In the Cinnamon desktop manager:

• go to the taskbar
• click on the the networking icon (looks like two plugs about to be connected (think of Michelangelo's creation of Adam but with generic plugs))
• it brings up a GUI panel right above the taskbar
• click "network settings"
• brings up a "Network" dialog
• click on your network interface
• click the gear icon
• brings up a new dialog
• on the left is a list of text names one should be named "Identity", click on "Identity"
• on the bottom make sure the "Connect Automatically" checkbox is enabled
• done
• bonus: restart and verify the network interface comes up after a restart

The command line method:

• disclaimer i haven't tested this method because this method uses the old ifconfig tools which are deprecated since about 2014 (or if you do lots of EL work 2014 coincides with centos7 release)
• get the name of the network interface
• sudo vim /etc/sysconfig/network-scripts/ifcfg-${name_of_interface}
  • ensure the key ONBOOT is present and set the value to yes

unfortunately these changes are not reflected in the GUI for some reason. so i do not trust this method so much and again this method depends on the deprecated ifconfig tools/methods. this might work but might not. the GUI method does change the value in this file so there's that.