Comment 1 for bug 2069111

Hello,

netplan doesn't touch that file, not sure why it gets reset. networkd might be the one responsible for that.

Have you tried to do that with sysctl?

Can you try to create a file like /etc/sysctl.d/99-ens3.conf with the following content:

net.ipv4.conf.ens3.route_localnet = 1

You can also add it to /etc/sysctl.conf

In my tests (on Ubuntu) this setting doesn't get reset after netplan apply.