Netplan configuration for network interface failover.

50-cloud-init.yaml

network:
  version: 2
  ethernets:
    enp9s0:
      dhcp4: false
  wifis:
    wlan0:
      access-points:
        "wifi":
          password: "pass"
      dhcp4: false
  bonds:
    bond0:
      interfaces: [enp9s0, wlan0]
      #macaddress: "xx:xx:xx:xx:xx:xx"
      dhcp4: true
      dhcp-identifier: mac
      dhcp4-overrides:
        use-dns: true
        use-domains: true
      ipv6-privacy: true
      parameters:
        mode: active-backup
        fail-over-mac-policy: none
        primary-reselect-policy: always
        primary: enp9s0
        mii-monitor-interval: 100
        min-links: 1