nanog mailing list archives
Re: NTP Issues Today
From: Jay Ashworth <jra () baylink com>
Date: Tue, 20 Nov 2012 14:28:19 -0500 (EST)
----- Original Message -----
From: "Leo Bicknell" <bicknell () ufp org>
To protect against two falseticking servers (tick and tock, as we saw on the 19th) you need _FIVE_ servers minimum configured if they are both in the list. More importantly, if you want to protect against a source (GPS, CDMA, IRIG, WWIV, ACTS, etc) false ticking, you need a minimum of _FOUR_ different source technologies in the list as well. It's not hard, my box that I posted the logs from peers with 18 servers using 8 source technologies, all freely available on the Internet...
I'm curious, Leo, what your internal setup looks like. Do you have an internal pair of masters, all slaved to those externals and one another, with your machines homed to them? Full mesh? Or something else? In my last big gig, it was recommended to me that I have all the machines which had to speak to my DBMS NTP *to it*, and have only it connect to the rest of my NTP infrastructure. It coming unstuck was of less operational impact than *pieces of it* going out of sync with one another... Cheers, -- jra -- Jay R. Ashworth Baylink jra () baylink com Designer The Things I Think RFC 2100 Ashworth & Associates http://baylink.pitas.com 2000 Land Rover DII St Petersburg FL USA #natog +1 727 647 1274
Current thread:
- Re: NTP Issues Today, (continued)
- Re: NTP Issues Today George Herbert (Nov 19)
- Re: NTP Issues Today Sid Rao (Nov 20)
- Re: [outages] NTP Issues Today Mike Lyon (Nov 19)
- Message not available
- Message not available
- Re: [outages] NTP Issues Today Colin Johnston (Nov 20)
- Message not available
- Re: [outages] NTP Issues Today Colin Johnston (Nov 20)
- Message not available
- Message not available
- RE: [outages] NTP Issues Today R. Benjamin Kessler (Nov 20)
- Re: NTP Issues Today Seth Mattinen (Nov 20)
- Re: NTP Issues Today Steve Meuse (Nov 20)
- Re: NTP Issues Today Leo Bicknell (Nov 20)
- Re: NTP Issues Today Jay Ashworth (Nov 20)
- Re: NTP Issues Today Jared Mauch (Nov 20)
- Re: NTP Issues Today George Herbert (Nov 20)
- Re: NTP Issues Today Leo Bicknell (Nov 20)
- Re: NTP Issues Today Darius Jahandarie (Nov 20)
- Re: NTP Issues Today Mike Lyon (Nov 20)
- Re: NTP Issues Today Jared Mauch (Nov 20)
- Picking outside NTP servers (Re: NTP Issues Today) Jay Ashworth (Nov 20)
- Re: Picking outside NTP servers (Re: NTP Issues Today) George Herbert (Nov 20)
- Re: Picking outside NTP servers (Re: NTP Issues Today) Majdi S. Abbas (Nov 20)