Date: Sun, 25 Oct 1998 01:14:02 -0800 From: Studded <Studded@gorean.org> To: Bryce Newall <data@dreamhaven.net> Cc: Dan Nelson <dnelson@emsphone.com>, Brendan Kosowski <brendan@bmk.com.au>, FreeBSD Questions <freebsd-questions@FreeBSD.ORG> Subject: Re: Time calibration ? Message-ID: <3632EBDA.FD5F1529@gorean.org> References: <Pine.NEB.3.96.981024182211.363c-100000@ds9.dreamhaven.org>
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Bryce Newall wrote: > > On Sat, 24 Oct 1998, Dan Nelson wrote: > > > For others, most likely much farther away, see > > http://www.eecis.udel.edu/~ntp/ and hit the "Public NTP Time Servers" > > link. > > Relating to this, do you (or anyone else) know of a listing of xntpd > peers? I'm currently peering with only one source, and I'd like to > "expand my horizons" a bit, in the event that I can't reach this one > particular peer (and it's happened before). Thanks! The use of peering for time synchronization is often misunderstood. The purpose of a peer network is to keep *your* machines in synch with one another, as opposed to the purpose of a server -> client relationship which is designed to keep your network in synch with an outside source. For instance, Bryce could synch ds9 and voyager as peers, while synching each to a stratum 2 server outside of his network. It's generally considered rude for an "average user" to synch to a stratum 1 server without permission. It's also essentially unecessary, as a good stratum 2 server will provide more accuracy than any of us will ever need. I generally try to set up a network using two or three stratum 2 servers as sources who are on different backbones. Usually 2 is enough, although depending on the importance of application I might use 3. Using more actually can become counter productive. If you have a large network of machines that need synchronization you should set up some time servers as stratum 3 servers inside your network synched to one another as peers, have them sych to the stratum 2 servers outside of your network and have your machines synch to your time servers. This is considered good netizenship as well. The documentation on ntp is pretty extensive, but if you're serious about setting up a time network it's well worth digging into. All of what you need to know is available at that web site and in the ntp/xntpd sources. To answer the other question, ntp stands for "Network Time Protocol" and is also a generic label to apply to the servers, clients, etc. The xntpd server supports version 3 of the protocol, ntpd is version 4. The two branches are relatively equivalent to our -Stable and -Current. At some point we should probably integrate ntp into -current, but the last time this topic came up (about 6 months ago) someone more knowledgeable than me was looking at both sets of sources and decided that ntp wasn't yet ready for prime time. For a long time I had hoped that someone would at least update to a more recent version of xntpd and then move that into the 2.2 branch, but that dream will die with 2.2.8. :-/ Our version of xntpd is prehistoric, and the vast numbers of bug fixes and algorithm improvements we're missing out on boggles the mind. And before anyone mentions it, I volunteered to make a port of the more recent version a while back and was told that it wouldn't be committed. If that has changed I'm still happy to do a port of the more recent version. Hope this helps, Doug -- *** Chief Operations Officer, DALnet IRC network *** To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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