Ubuntu Server Missing Network Interface

I had an opportunity recently to install Ubuntu Server on a very old server, a Dell R710 that had 4 native network interfaces and 4 add-on network interfaces, resulting in a total of 8 network interfaces.

During the installation process, the installer did recognize all the physical network interfaces on the machine but because it did not successfully acquire DHCP addresses, I was forced to install Ubuntu without networking.

After the installation, only the loop back (lo) interface existed and all the other physical interfaces were missing. I had to use the netplan command to create the interfaces. This article was of tremendous help. I pretty well just followed its instructions.

I first created the 99-disable-network-config.cfg file with the contents as instructed by the article.

sudo su -

echo "network: {config: disabled}"  >>  /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg

Followed by editing the 50-cloud-init.yaml file with the following contents:

vim /etc/netplan/50-cloud-init.yaml

# This file is generated from information provided by
# the datasource. Changes to it will not persist across an instance.
# To disable cloud-init's network configuration capabilities, write a file
# /etc/cloud/cloud.cfg.d/99-disable-network-config.cfg with the following:
# network: {config: disabled}
network:
  version: 2
  renderer: networkd
  ethernets:
    eno1:
      dhcp4: true

Once netplan is configured, I then executed the following command:

netplan generate
netplan apply

Once I rebooted the computer, the eno1 network interface now exists with a provisioned IP from my local DHCP server.

Much of the content in this blog is a verbatim reference from the article but I provided here so that it is more easily searched by me if I ever needed it in the future.