nanog mailing list archives
Re: NTP question
From: Brandon Martin <lists.nanog () monmotha net>
Date: Wed, 1 May 2019 18:44:18 -0400
On 5/1/19 5:35 PM, Harlan Stenn wrote:
- Why do folks want to have one or more NTP server masters that have at least 1 refclock on them in a data center, instead of having their data center NTP server masters that only get time over the internet?
It can be extremely useful to have known-good timestamps to within several milliseconds, even in the event of a connectivity outage, when trying to figure out what went wrong from log entries spanning multiple systems and sites.
Think about what might happen if you lost time sync as a result of the incident causing said connectivity outage. Depending on your time sources available, you might see rapid drift or, worst case, lose your time reference entirely as a result of equipment restarts, etc. GPS, as long as you have a good view of the sky, provides extremely accurate "lights out" time info, both absolute and relative, from a single source with no (mostly) strings attached for that purpose.
-- Brandon Martin
Current thread:
- Re: NTP question, (continued)
- Re: NTP question Harlan Stenn (May 01)
- Re: NTP question william manning (May 02)
- Re: NTP question Tom Beecher (May 02)
- Re: NTP question Valdis Klētnieks (May 02)
- RE: NTP question Kain, Rebecca (.) (May 02)
- Re: NTP question Grant Taylor via NANOG (May 02)
- Re: NTP question Alain Hebert (May 02)
- Re: NTP question Grant Taylor via NANOG (May 02)
- Re: NTP question Alain Hebert (May 02)
- Re: NTP question Mike Hammett (May 01)
- Re: NTP question Brandon Martin (May 01)
- Re: NTP question Harald Koch (May 01)
- Re: NTP question Brandon Martin (May 01)
- Re: NTP question Harlan Stenn (May 01)
- Re: NTP question Harald Koch (May 01)
- RE: NTP question Keith Medcalf (May 01)
- Re: NTP question William Herrin (May 01)
- Re: NTP question Rubens Kuhl (May 01)
- RE: NTP question Keith Medcalf (May 01)
- Re: NTP question Harlan Stenn (May 01)
- Re: NTP question Stephen Satchell (May 01)