Enabling and disabling Ethernet in ubuntu 15.10

Question

On my dell laptop, ethernet once disconnected cannot resume the connection again without restart.

This same problem is on Windows also, meaning definitely the problem is not with Ubuntu. But on Windows I used to disable the Ethernet and again enable the ethernet in control panel -> network....

Question :

How can I disable & enable the ethernet in Ubuntu?

I guess this way I may solve my problems and save time.

Solution

This tutorial is for Ubuntu Unity (the default version/download). If you have another flavor (MATE, KDE, GNOME, etc.), comment on this answer and I will update it.

1. Click the gear and wrench icon in the launcher to open System Settings. If you can't find this icon, or it isn't there, just search for it in the Dash (~Start Menu).
2. Once Settings opens, double click the Network tile.
3. Once there, select the Wired or Ethernet option in the panel on the left.
4. Toward the top right of the window, there will be a switch that says On. Flip it off.

That should disable the adapter. Just turn the switch back on to reset it.

Terminal Method (advanced, but works for all flavors)

1. Open a terminal by pressing Ctrl+Alt+T.
2. In the terminal, type sudo ip link set down eth0.
3. Enter your password when prompted and hit Enter (NOTE: you will not see anything being entered. This is a security feature, and your password is indeed being entered.)
4. Now, enable the Ethernet adapter by running sudo ip link set up eth0.

If you need any clarification, or have a different version of Ubuntu than Unity, please leave a comment and I'll do my best to help :-).

Comments

[frepie]

on 16.04, interfaces are renamed by grub, so eth0 is not recognized. On top of that the new name is also not recognized.

[Alexis Wilke]

That works for me, I can enable the NIC that appears disabled, but only until the next reboot... Any idea what could cause the OS to decide to turn off (disable) a NIC like that?