Hi,
I want to change systemctl default-hierarchy from legacy to hybrid. What is the best method to change this setting easily?
Thanks.

1. You give no context at all
2. You don't tell us waht you tried and why it didn't work
3. Have you read the manual, have you searched? I just did, there seems to be no immediate search results and the systemctl man page does not mention the term "hierarchy" at all.

PS: 'man systemd' does mention 'hierarchy' several times. I suggest you start there.

Thats what I want to achieve:
Case I
In ubuntu 18.04 LTS and upwards, 'systemctl --version' is something like that:
So in that output default-hierarchy looks hybrid. So if you use systemd-networkd and put the following statement in the .network configuration file the interface turns to DOWN state after rebooting.
Case II
In Centos 8, 'systemctl --version' output is:
In this output, when you use Unmanaged=yes does not turn the network interface to DOWN state.
So I suppose that if we could change the default-hierarchy effects that parameter. What do you think? Any idea?

Regards.

The 'systemctl --version' output seems to refer to compile-time options, so you'd need to recompile systemd to change that.

More generally:
Frankly, I have no idea what default-hierarchy even means here.