Sharing Wifi Connection with Wired Connection

If using a laptop and connecting to the internet over wifi, you might want to share that connection with wired only devices, for example desktop voip phones, other machines with only a network card etc.

Thankfully this is really easy to do:

Press Apply and then go to a terminal. Type nm-connection-editor and you should get a window like this:


We can add a shared network connection by pressing the Add button. Do the following afterwards:

Choose Ethernet from the list and press Create…
click IPv4 Settings
Choose Shared to other computers in the Method drop-down menu
Enter Share via ethernet as the Connection name at the top (or choose a name you prefer)
When that’s all done, you can close the Network Connections menu we opened via the terminal. Now open the Network control panel once more. It should have two profiles for your ethernet connection now (mine is a USB ethernet device):


If it’s not already selected, just click on the Share via ethernet text. NetworkManager will automatically configure NAT, DHCP and firewall rules for you. When you’re ready to go back to normal ethernet operation and you want to stop sharing, simply click on the other profile (mine is called Home USB Ethernet). NetworkManager will put the ethernet device back into the original way you had it configured (default is DHCP with automatic IPv6 via SLAAC).

copied from: https://major.io/2015/03/29/share-a-wireless-connection-via-ethernet-in-gnome-3-14/