Starlink has enabled an NTP server in their dishes that serves GPS time at Stratum 1. Folks with Starlink installs can connect to it on their LAN at 192.168.100.1.
I’ve tried a quick test of a few minutes and it look like it works well, my chronyc is syncing to it now in preference to the Ubuntu NTP pool servers. Haven’t run it long enough to have meaningful statistics.
Apologies if this seems off-topic, but there’s about 2.7M installs of Starlink in the world and it seems like big news they all have access to GPS time. Not sure it’s so useful to pool users though: the high latency jitter makes a Starlink connection not such a great place to run an NTP server.
I wonder how many Starlink users will ever enable using its server. One nice thing about the NTP pool is how automatic it is: any major software vendor now has preconfigured NTP pool server (or Microsoft/Apple). I wonder if there’s a safe way to sneak 192.168.100.1 into DNS entries, that sounds like a terrible idea.
Non-global IP addresses must not appear for public-used DNS domains because they are unreachable in many situations.
Even when 10 million people use Starlink, billions don’t and won’t be able to reach the server.
DHCP exists for both IPv4 and IPv6 which can deliver an option for NTP.
This is the right way to handle this situation.
That’s interesting indeed. I’m guessing most Starlink users don’t have an ethernet connection to their dish, as the first models required an accessory to provide that connection. The latest mainstream model does have ethernet built-in, so at least some savvy users will be configuring it with a wired connection to provide more than one WiFi AP and avoid another layer of IPv4 NAT.
If you care about NTP service better than a few milliseconds, WiFi is also a bit too jittery, at least by default.
From my perspective, the most interesting pool use case for the dish-based NTP service is for people using Starlink as a fallback to a decent wired connection. One could host a pool NTP server on addresses from the primary ISP which uses the Starlink NTP among other sources. When the primary is working well, pool clients could get pretty decent service.
FWIW here’s a graph of RMS offset and Root dispersion. Before 10:30 (the vertical line) I was syncing chrony via Starlink Internet to various pool servers and getting an average of about 400µs RMS. After I’m syncing to Starlink GPS and it’s down to 85µs and still converging.
I’m on wired ethernet. I actually don’t know, what kind of RMS would you expect on a stratum 2 Linux PC with a LAN connection to a GPS? It’s all cheap consumer PC hardware and gigabit ethernet, this chrony is running in a VM. I’m genuinely surprised how well chrony did syncing to the pool, particularly given Starlink’s latency jitter.
