How to get eth0 and wlan0 back on Ubuntu Mate 18.04?

[Bo Berglund]

On Sun, 31 Jan 2021 00:12:35 +0100, Bo Berglund <bo.berglund at gmail.com> wrote:

>On Fri, 29 Jan 2021 16:39:39 +0100, Tom H <tomh0665 at gmail.com> wrote:
>
>>On Wed, Jan 27, 2021 at 10:20 AM Bo Berglund <bo.berglund at gmail.com>
>>wrote:
>>>
>>> I have a repurposed laptop running Ubuntu Mate 18.04.5 LTS and I
>>> need to run a lot of scripts on this, but they fail because for
>>> some reason eth0 and wlan0 are no longer available...
>>>
>>> How can I re-enable the use of these standard names instead of the
>>> new strange names?
>>>
>>> I have searched the net and found some instructions here:
>>> https://www.itzgeek.com/how-tos/mini-howtos/change-default-network-name-ens33-to-old-eth0-on-ubuntu-16-04.html
>>>

...

>>> So how can I handle the rename of the network and still not destroy whatever the
>>> existing entry is meant to do?
>>
>>GRUB_CMDLINE_LINUX="resume=UUID=<long guid string> net.ifnames=0 biosdevname=0"
>
>Thanks a lot, I will try this.
>

When I got back into this I found that the next steps after editing grub
according to my notes is:

sudo grub-mkconfig -o /boot/grub/grub.cfg

and then:
sudo nano /etc/network/interfaces

Here the file is supposed to be modified by setting it thus:

auto eth0
iface eth0 inet dhcp

However nothing is said about wlan0 in my notes and my existing file looks like
this:

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

Should I change it to become like this:

# interfaces(5) file used by ifup(8) and ifdown(8)
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

auto wlan0
iface wlan0 inet dhcp

I.e. just add the two new names onto the end of the file?

I have not yet made any of the changes because currently the laptop is using
wifi and I access it via PuTTY ssh (and VNC) so I need to make sure I do not
break any networking before I finalize the changes and reboot.


-- 
Bo Berglund
Developer in Sweden