Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) Options for DHCPv6
"David L. Mills" <mills@udel.edu> Mon, 19 November 2007 05:17 UTC
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Date: Mon, 19 Nov 2007 05:17:33 +0000
From: "David L. Mills" <mills@udel.edu>
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Subject: Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) Options for DHCPv6
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Danny, As I understand it, the DHCP client broadcasts a request to the DHCP server and receives a response. There is an opportunity for the DHCP client to measure the delay, should it be so instrumented. In no way did I intend the DHCP server run NTP for any business but itself. The discussion has left me a little uneasy about the specificy of the message formats to the current NTP implementation. Things like minpoll and maxpoll could be interpreted in context to protect the NTP servers, but in the DHCP environment that probably is not an issue. There is no real need to reveal broadcast mode servers. As long as the client knows the address mask, it can generate the broadcast address to listen on. It doesn't make sense to advertise symmetric modes, as these are usually reserved for serious low-stratum campus servers. This leaves only client/server mode as useful. However, the key ID is important, as the NTP client and server should share the same bag of keys and the client might not know the current server key ID. Some perspective on the issues can be gained from our experience with other discovery schemes like broadcast, manycast and the pool. Broadcast provides the server address (for delay measurements), stratum and key ID. Manycast servers filter the client stratum and respond only if they can provide better time. They also provide the key ID. The pool scheme merely provides the server addresses. In all three schemes the client can filter the responses for acceptable stratum and then cast out the survivors from the population leaving only the best quality survivors. The DHCP discovery scheme needs only to provide comparable statistics. A client can use any combination of these schemes. Dave Danny Mayer wrote: > Dave, > > I don't see how. The DHCP server and the NTP server are different nodes > on the network, unless the DHCP server is going to provide the NTP > service as well but that's a bad assumption to make even though the DHCP > server SHOULD be running NTP, if only for itself. > > Danny > > David L. Mills wrote: > >> Brian, >> >> We need to think about scenarios for server discovery. Without prejudice >> on the message formats, a virgin client might be directed to either: >> >> 1. Listen for broadcast/multicast on <address> and do/do not execute a >> volley. I like the delay field to enable/disable that and have added it >> to ntpd. In principle, the delay can be determined from the DHCP packets >> themselves, a feature that might be added. >> _______________________________________________ dhcwg mailing list dhcwg@ietf.org https://www1.ietf.org/mailman/listinfo/dhcwg
- [dhcwg] Network Time Protocol (NTP) Options for D… Benoit Lourdelet (blourdel)
- [dhcwg] RE: [ntpwg] Network Time Protocol (NTP) O… Benoit Lourdelet (blourdel)
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Bud Millwood
- [dhcwg] Re: [ntpwg] Digital Evidence Standards an… Shane Kerr
- [dhcwg] RE: [ntpwg] Network Time Protocol (NTP) O… Mark Elliot
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Harlan Stenn
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Brian Utterback
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Brian Utterback
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… David L. Mills
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Brian Utterback
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… David L. Mills
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… TS Glassey
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Brian Utterback
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… David L. Mills
- [dhcwg] Digital Evidence Standards and a statemen… TS Glassey
- [dhcwg] Re: [ntpwg] Digital Evidence Standards an… TS Glassey
- [dhcwg] Re: Digital Evidence Standards and a stat… David L. Mills
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ted Lemon
- [dhcwg] Re: [ntpwg] Network Time Protocol (NTP) O… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ralph Droms
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David L. Mills
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ted Lemon
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Brian Utterback
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Brian Utterback
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ted Lemon
- RE: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Benoit Lourdelet (blourdel)
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ralph Droms
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Harlan Stenn
- RE: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Benoit Lourdelet (blourdel)
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Mark Stapp
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David W. Hankins
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David W. Hankins
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Mark Andrews
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Mark Andrews
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Mark Andrews
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Bud Millwood
- RE: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Benoit Lourdelet (blourdel)
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… M. Warner Losh
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- RE: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Benoit Lourdelet (blourdel)
- RE: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… anthony.flavin
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David W. Hankins
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Mark Stapp
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… TS Glassey
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brian Utterback
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… David W. Hankins
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Mark Stapp
- Re: [dhcwg] Re: [ntpwg] Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David L. Mills
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brad Knowles
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Danny Mayer
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Hal Murray
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brad Knowles
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brad Knowles
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- RE: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… anthony.flavin
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… David W. Hankins
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Josh Littlefield
- RE: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Brzozowski, John
- Re: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Ted Lemon
- Re: [dhcwg] Network Time Protocol (NTP) Options f… Bud Millwood
- Re: [dhcwg] Network Time Protocol (NTP) Options f… Mark Stapp
- Re: [dhcwg] Network Time Protocol (NTP) Options f… Ted Lemon
- RE: [ntpwg] [dhcwg] Re: Network Time Protocol (NT… Woundy, Richard
- Re: [dhcwg] Network Time Protocol (NTP) Options f… Danny Mayer
- RE: [ntpwg] [dhcwg] Network Time Protocol (NTP) O… Richard Gayraud (rgayraud)
- Re: [ntpwg] [dhcwg] Network Time Protocol (NTP) O… Brian Utterback
- Re: [ntpwg] [dhcwg] Network Time Protocol (NTP) O… Brad Knowles
- RE: [ntpwg] [dhcwg] Network Time Protocol (NTP) O… anthony.flavin
- Re: [ntpwg] [dhcwg] Network Time Protocol (NTP) O… Danny Mayer