Ubuntu 18.04+ Server: Use MAC Address for DHCP

[datallboy]

Sometimes Ubuntu 18.04 server will not use the MAC address for DHCP connections. To enable this, you need to edit your netplan file located at /etc/netplan/xxx.yaml and add the dhcp-identifier: mac setting.

Example:

network:
  ethernets:
    eth0:
      dhcp4: true
      dhcp-identifier: mac
  version: 2

Then run sudo netplan apply to apply the new settings.

Source: Jim Mendenhall [https://www.starryhope.com/notes/ubuntu-18.04-server-use-mac-for-dhcp/]