nanog mailing list archives
RE: Need trusted NTP Sources
From: Matthew Huff <mhuff () ox com>
Date: Fri, 7 Feb 2014 10:56:35 -0500
Working in the financial world, the best practices is to have 4 ntp servers (if not using PTP). 1) You need 3 to determine the correct time (and detect bad tickers) 2) If you lose 1 of the 3 above, then you no longer can determine the correct time 3) Therefore with 4, you have redundancy. We have two Symmetricom Stratum 1 time servers synced via GPS with Rubidium oscillators, and two RHEL 6 servers running ntpd for our 4 servers. ---- Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 -----Original Message----- From: Roy [mailto:r.engehausen () gmail com] Sent: Friday, February 7, 2014 10:23 AM To: nanog () nanog org Subject: Re: Need trusted NTP Sources On 2/7/2014 3:35 AM, Saku Ytti wrote:
On (2014-02-06 21:14 -0500), Jay Ashworth wrote:My usual practice is to set up two in house servers, each of which talks to: And then point everyone in house to both of them, assuming they accept multiple server names.Two is worst possible amount of NTP servers to have. Either one fails and your timing is wrong, because you cannot vote false ticker. And chance of either of two failing is higher than one specific of them.
"A man with a watch knows what time it is. A man with two watches is never sure."
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Current thread:
- Re: Need trusted NTP Sources, (continued)
- Re: Need trusted NTP Sources Nick Hilliard (Feb 06)
- Re: Need trusted NTP Sources Chris Adams (Feb 06)
- Message not available
- Re: Need trusted NTP Sources Notify Me (Feb 06)
- Re: Need trusted NTP Sources Aled Morris (Feb 06)
- Re: Need trusted NTP Sources Mark Milhollan (Feb 06)
- Re: Need trusted NTP Sources Jay Ashworth (Feb 06)
- Re: Need trusted NTP Sources Saku Ytti (Feb 07)
- Re: Need trusted NTP Sources Jimmy Hess (Feb 07)
- Re: Need trusted NTP Sources Jay Ashworth (Feb 08)
- Re: Need trusted NTP Sources Roy (Feb 07)
- RE: Need trusted NTP Sources Matthew Huff (Feb 07)
- Re: Need trusted NTP Sources Jared Mauch (Feb 07)
- Re: Need trusted NTP Sources Anthony Williams (Feb 07)
- You need a VLAN to the foot of NIST ITS services - no problem - we got you covered. Re: Need trusted NTP Sources TGLASSEY (Feb 07)
- Re: Need trusted NTP Sources Bryan Seitz (Feb 07)
- Re: Need trusted NTP Sources Majdi S. Abbas (Feb 08)
- Re: Need trusted NTP Sources Jay Ashworth (Feb 08)
- Re: Need trusted NTP Sources Jay Ashworth (Feb 08)
- Re: Need trusted NTP Sources Saku Ytti (Feb 09)
- Re: Need trusted NTP Sources Andriy Bilous (Feb 09)
- Re: Need trusted NTP Sources Saku Ytti (Feb 09)