I take a simple example: systemd-timesyncd.serviceThis service is responsible to keep time accurate (like the regular NTP server, but it only act as a lightweight client, and synchronize to only one server at a time).The default configuration file /etc/systemd/timesyncd.conf is empty so the compile-time parameters are used.If I download the source code, I can see what are the default parameters.If I get my specific distribution (Debian) patches I can see the custom default parameters (if any).  For example the NTP servers used by default are time{1,2,3,4}.google.comAnd Debian replace them by {0,1,2,3}.debian.pool.ntp.org at compile-time.I can see which server is currently used: systemctl status systemd-timesyncd.serviceThis allow to have an idea about the default configuration. But this is far incomplete, even if it is probably often easy to guess the remaining servers.Question: is there a standard way to display the default parameters for a systemd service?  
systemd: how to print a service's default configuration?
systemd;configuration
Question: is there a standard way to display the default parameters for a systemd service?There is no standard way to display the default parameters for a systemd service.Many services expose some parameters on the bus.For example:busctl call org.freedesktop.systemd1 /org/freedesktop/systemd1 org.freedesktop.DBus.Properties GetAll s shows properties of the manager itself.Output contains RuntimeWatchdogSec, ShutdownWatchdogSec(as RuntimeWatchdogUSec and ShutdownWatchdogUSec), LogLevel, DefaultStandardOutput, DefaultStandardError etc.I take a simple example: systemd-timesyncd.serviceSee: https://github.com/systemd/systemd/issues/1589