Date: Wed, 12 Dec 2001 11:46:27 -0800 From: "Kevin Oberman" <oberman@es.net> To: devin-freebsdquestions@rintrah.org Cc: The Anarcat <anarcat@anarcat.dyndns.org>, freebsd-questions@FreeBSD.ORG Subject: Re: ntpdate works, ntpd does not Message-ID: <200112121946.fBCJkRd11801@ptavv.es.net> In-Reply-To: Your message of "Wed, 12 Dec 2001 12:39:46 EST." <20011212123946.A30482@tharmas.rintrah.org>
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> Date: Wed, 12 Dec 2001 12:39:46 -0500 > From: devin-freebsdquestions@rintrah.org > Sender: owner-freebsd-questions@FreeBSD.ORG > > On Wed, Dec 12, 2001 at 10:53:11AM -0500, The Anarcat wrote: > > Hi > > > > I've been struggling with a particularly painful problem with my ntpd > > here. I am able to adjust the clock using "ntpdate" without any > > problems: > > > > # ntpdate time.nist.gov > > 12 Dec 10:40:57 ntpdate[1152]: adjust time server 192.43.244.18 offset -0.059697 sec > > # > > > > but ntpd always fails. From tcpdump, I can see it communicating with the > > server, but just once. Here is the showpeer output: > > > > ntpdc> showpeer time.nist.gov > > remote 192.43.244.18, local 6.0.0.0 > > hmode client, pmode unspec, stratum 16, precision -20 > > leap 11, refid [0.0.0.0], rootdistance 0.00000, rootdispersion 0.00000 > > ppoll 10, hpoll 6, keyid 0, version 4, association 43316 > > valid 0, reach 000, unreach 1, flash 0x0000, boffset 0.00400, ttl/mode 0 > > timer 0s, flags config, bclient > > reference time: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000 > > originate timestamp: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000 > > receive timestamp: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000 > > transmit timestamp: bfc1f728.6a9984a0 Wed, Dec 12 2001 10:32:56.416 > > filter delay: 0.00000 0.00000 0.00000 0.00000 > > 0.00000 0.00000 0.00000 0.00000 > > filter offset: 0.000000 0.000000 0.000000 0.000000 > > 0.000000 0.000000 0.000000 0.000000 > > filter order: 7 6 5 4 > > 3 2 1 0 > > offset 0.000000, delay 0.00000, error bound 0.00000, filter error 4.00000 > > > > Here is the tcpdump output I get: > > > > 10:45:57.912825 MTL-HSE-ppp191859.qc.sympatico.ca.ntp > time.nist.gov.ntp: v4 client strat 0 poll 6 prec -20 [tos 0x10] > > 10:45:58.084038 time.nist.gov.ntp > MTL-HSE-ppp191859.qc.sympatico.ca.ntp: v4 server strat 1 poll 6 prec -18 [tos 0x10] > > > > I pay a beer to anyone passing through montreal and solving this thing, > > as it's getting me completly mad. > > > > Note that I am behind NAT+ipfw. But I kinda opened the rules to run my > > tests... :) Anyways, the packets *are* coming to and fro, both with > > ntpdate and ntpd. > > > > I believe ntpd will poll the server over a period of some time to get a feel > for drift. I know when I set it up it took several hours before it would > adjust the clock. How long are you waiting before you expect ntpd to make adjustments? More specifically, it polls once every 64 seconds it has enough samples to be statistically significant. This usually takes 5 samples. It then starts drifting the clock, if needed. To watch this happen, use the command "ntpq -p". When a server is tagged with a symbol, it's considered for use. The one marked '*' is the one being used and those marked '+' are also considered "good". IF the source and the sync to the local system are stable, the time between polls will increase to 1024 seconds between polls. R. Kevin Oberman, Network Engineer Energy Sciences Network (ESnet) Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab) E-mail: oberman@es.net Phone: +1 510 486-8634 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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