Feature Request: Support for Source Prioritization/Weighting

[upmcplanetracker]

I use ntpd-rs on a mobile laptop running Ubuntu 26.04 that toggles between a home network that runs NTP intercept via a Firewalla Gold Plus router (with a local server at 192.168.1.1) and public Wi-Fi (where I rely on nts servers).

Currently, the daemon treats all configured sources as equal candidates for synchronization once they are reachable. This means that even when I am at home, the daemon might occasionally prefer the external NTS sources or spend time balancing between them, rather than strictly pinning to the local, low-latency Firewalla source.

Requested Feature:
It would be ideal to have a priority or weight field in the [[source]] configuration.

High priority sources would be used exclusively if reachable.

If high priority sources are unreachable, the daemon would fall back to lower priority/secondary sources.

This would ensure my mobile device maintains the most consistent time-sync behavior based on the network environment it is currently in.

I have currently found a way around this with my laptop config as such:

# NTS Servers - These will "fail" at home due to Firewalla Intercept
[[source]]
mode = "nts"
address = "[time.cloudflare.com](http://time.cloudflare.com/)"

[[source]]
mode = "nts"
address = "[ntppool1.time.nl](http://ntppool1.time.nl/)"

[[source]]
mode = "nts"
address = "[ptbtime1.ptb.de](http://ptbtime1.ptb.de/)"

# Home Source
[[source]]
mode = "server"
address = "192.168.1.1"

[synchronization]
minimum-agreeing-sources = 1

but I'm wondering if there's a more elegant way than that.

thank you for all the hard work.

[davidv1992]

Apologies for the somewhat late response. We are currently looking into what we want in this area, but haven't made concrete decisions yet.

[upmcplanetracker]

I appreciate the hard work you guys do on this.