reassign 1052535 cloud-init Thank you for your bug report. Checking the Netplan source code, it should not be able to generate a systemd-networkd configuration broken in this specific way.
IIUC from message #10, you're using cloud-init network config "version: 1", which means cloud-init will directly generate the systemd-networkd configuration. Cloud-init's passthrough to Netplan is only used on network config "version: 2". Another indication for that is your generated networkd configuration file is generated in: /etc/systemd/network/10-cloud-init-eth0.network: Netplan would instead generate a config file in: /etc/systemd/network/10-netplan-eth0.network I'm re-assigning the bug report to cloud-init.
