Each failover IP address will need its own line in the configuration file. The configuration file is called “50-cloud-init.yaml” and is located in /etc/netplan.
Determine Ubuntu NIC interface
Create Ubuntu configuration Network file
Edit Ubuntu Network file using your favorite editor like nano
Now, edit the file with the content below, replacing INTERFACE_NAME MAC_ADDRESS and FAILOVER_IP:
version: 2 ethernets: INTERFACE_NAME: dhcp4: true match: macaddress: MAC_ADDRESS set-name: INTERFACE_NAME addresses: - FAILOVER_IP/32
Apply changes to Ubuntu Network