nanog mailing list archives
Re: NTP Sync Issue Across Tata (Europe)
From: John Gilmore <gnu () toad com>
Date: Tue, 08 Aug 2023 13:57:32 -0700
I was also speaking specifically about installing GPS antennas in viable places, not using a facility-provided GPS or NTP service.
Am I confused? Getting the time over a multi-gigabit Internet from a national time standard agency such as NIST (or your local country's equivalent) should produce far better accuracy and stability than relying on locally received GPS signals. GPS uses very weak radio signals which are regularly spoofed by all sorts of bad actors: https://www.gps.gov/spectrum/jamming/ for all sorts of reasons (like misleading drone navigation): https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incident Depending on satnav systems creates a large single point of failure for worldwide civilian infrastructure. Jamming GPS with subtly fake time data near big data centers seems like an easy move that would cause all sorts of distributed algorithms to start failing in unusual ways. And in a more serious wartime attack, many or most GPS satellites themselves would be destroyed or disabled. Yet digital radio modulations like FT8 or DMR rely on tight time synchronization among different transmitters. So do many modern cellphone modulations -- not to mention distributed database sync algorithms. Depending on any of these for emergency communications when their time comes from GPS, is a recipe for having no communications during wars or cyber-wars in which GPS satellites are attacked or jammed. See a longer explanation here: https://www.ardc.net/apply/grants/2020-grants/grant-ntpsec/ I suspect that even today, if you rely on civilian GPS time near the US White House, Pentagon, or other military targets like bases, you will discover "anomalies" in the local radio GPS data, compared to what you get from an authenticated time standard over NTP. How reliable is civilian GPS time in Ukraine these days? John
Current thread:
- Re: NTP Sync Issue Across Tata (Europe), (continued)
- Re: NTP Sync Issue Across Tata (Europe) Rubens Kuhl (Aug 07)
- Message not available
- Re: NTP Sync Issue Across Tata (Europe) Rubens Kuhl (Aug 07)
- Re: NTP Sync Issue Across Tata (Europe) James R Cutler (Aug 06)
- Re: NTP Sync Issue Across Tata (Europe) Mark Tinka (Aug 07)
- Re: NTP Sync Issue Across Tata (Europe) Mike Hammett (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Mel Beckman (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Mike Hammett (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Mel Beckman (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Mike Hammett (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Mel Beckman (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) John Gilmore (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Martin Hannigan (Aug 08)
- Re: NTP Sync Issue Across Tata (Europe) Forrest Christian (List Account) (Aug 09)
- Re: NTP Sync Issue Across Tata (Europe) Seth Mattinen via NANOG (Aug 09)
- Re: NTP Sync Issue Across Tata (Europe) Jay Hennigan (Aug 09)
- Re: NTP Sync Issue Across Tata (Europe) Chris Adams (Aug 09)
- Re: NTP Sync Issue Across Tata (Europe) Mel Beckman (Aug 09)
- Re: NTP Sync Issue Across Tata (Europe) Forrest Christian (List Account) (Aug 09)
- Re: NTP Sync Issue Across Tata (Europe) Jay R. Ashworth (Aug 13)
- Re: NTP Sync Issue Across Tata (Europe) Forrest Christian (List Account) (Aug 13)
- Re: NTP Sync Issue Across Tata (Europe) Jay R. Ashworth (Aug 13)