[Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-ntp-using-nts-for-ntp-27.txt
Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de> Tue, 31 March 2020 06:00 UTC
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Date: Tue, 31 Mar 2020 08:00:17 +0200
From: Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>
To: "ntp@ietf.org" <ntp@ietf.org>, mlichvar@redhat.com
References: <20200326201030.397D340605C@ip-64-139-1-69.sjc.megapath.net> <9B282475-3DE0-46B9-9184-43351772E6F3@netnod.se> <00a66f26-a079-2650-9c7b-285b026269e3@nwtime.org> <24990_1585556439_5E81ABD7_24990_85_1_20200330081958.GB17158@localhost>
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Subject: [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-ntp-using-nts-for-ntp-27.txt
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>>> Miroslav Lichvar <mlichvar@redhat.com> schrieb am 30.03.2020 um 10:19 in Nachricht <24990_1585556439_5E81ABD7_24990_85_1_20200330081958.GB17158@localhost>: > On Fri, Mar 27, 2020 at 12:47:06AM ‑0700, Harlan Stenn wrote: >> On 3/27/2020 12:15 AM, Ragnar Sundblad wrote: >> >> On 26 Mar 2020, at 21:10, Hal Murray <hmurray@megapathdsl.net> wrote: >> >> It would also make sense for sites that are up 24/7 to do something like > once >> >> a day, scan the list of pool servers currently in use and kick out the > worst >> >> one and try a new one. The idea is to gradually pick servers that are > better, >> >> probably nearer, but distance measured in network performance rather than >> >> kilometers. >> > >> > Sounds like a very good idea! >> > >> > (I suppose you should take into consideration especially jitter, but also >> > loss, and the larger the round trip, the higher the risk for large >> > asymmetries = phase error and phase variations when routing change, >> > and the current measured phase error should probably also take into >> > account, and there are probably other things. Interesting problem!) >> >> This has always been part of the 'pool' directive in the Reference >> Implementation. > > Are you sure it does that? If ntpd automatically replaced the worst > performing servers (e.g. by root distance or jitter), it would break > the load balancing of pool.ntp.org. It shouldn't be a default > behavior of clients using the pool. (With other pools it might be ok.) AFAIK, it work like this: ntpd picks a set of servers (say 6) and start using them. Some of those may be flagged with '-' or may be unreachable. ntpd replaces those with a new pool query to fill up the slots and the process repeats. I think the corresponding log messages (if loglevel macthes) are: #sever pick a new host 21 Mar 10:40:14 ntpd[15087]: Soliciting pool server 172.20.16.4 #server drops a host 21 Mar 13:20:12 ntpd[15087]: 172.20.16.36 local addr 172.20.16.35 -> <null> The example is manycast, but pools should be very similar. Regards, Ulrich > > ‑‑ > Miroslav Lichvar > > _______________________________________________ > ntp mailing list > ntp@ietf.org > https://www.ietf.org/mailman/listinfo/ntp
- [Ntp] I-D Action: draft-ietf-ntp-using-nts-for-nt… internet-drafts
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Miroslav Lichvar
- [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-ntp-… Ulrich Windl
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Salz, Rich
- Re: [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Miroslav Lichvar
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Miroslav Lichvar
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Miroslav Lichvar
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Miroslav Lichvar
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Hal Murray
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Hal Murray
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Hal Murray
- [Ntp] Antw: Re: Antw: [EXT] Re: I-D Action: draft… Ulrich Windl
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-ntp-… Ulrich Windl
- Re: [Ntp] Antw: Re: Antw: [EXT] Re: I-D Action: d… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Harlan Stenn
- Re: [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-… Ragnar Sundblad
- [Ntp] Antw: Re: Antw: [EXT] Re: I-D Action: draft… Ulrich Windl
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Ragnar Sundblad
- Re: [Ntp] I-D Action: draft-ietf-ntp-using-nts-fo… Miroslav Lichvar
- [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-ntp-… Ulrich Windl
- Re: [Ntp] Antw: [EXT] Re: I-D Action: draft-ietf-… Miroslav Lichvar