nanog mailing list archives

Re: Need trusted NTP Sources


From: Jay Ashworth <jra () baylink com>
Date: Sat, 8 Feb 2014 19:48:49 -0500 (EST)

---- Original Message -----
From: "Matthew Huff" <mhuff () ox com>

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.

As I've noted, I had *nine* external peers; 3 shared by both machines
(commercial and NIST strat-1's), and 3 each from us.pool, which were
generally different servers; I did keep an eye on that.

And the NTP servers were monitored.

I'm stupid, but I'm not crazy. :-)

Cheers,
-- jra

-- 
Jay R. Ashworth                  Baylink                       jra () baylink com
Designer                     The Things I Think                       RFC 2100
Ashworth & Associates       http://www.bcp38.info          2000 Land Rover DII
St Petersburg FL USA      BCP38: Ask For It By Name!           +1 727 647 1274


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