[ntp:questions] zeroconf for ntpd?

Steve Kostecke kostecke at ntp.isc.org
Wed May 23 02:31:59 UTC 2007

Wolfgang S. Rupprecht wrote:

>"Steve Kostecke" wrote:
>> Manycasting uses network broadcast or multicast addresses for server
>> detection. While this is trivial on a LAN or WAN, manycasting over
>> the Internet will require ubquitous multicast support.
> I notice that ntp.isc.org does have an AAAA record and answers ntp
> queries on its IPv6 address. I wonder if the powers that be would be
> willing to allow it to be a IPv6 multicast server.

Multicast and Manycast modes are completely different; I believe that
you may be confusing the two.


* A Multicast server sends an NTP packet to the multicast address every
64 seconds.

* A Multicast client listens on the multicast address for an NTP packet

* Setting up the Multicast association involves a brief unicast phase
(during which the authentication is set up and the broadcast delay is
calculated). Once the unicast phase is complete the association switches
to multicast and the reverts to listening for the NTP packets on the
multicast address.


* A Manycast server waits to be discovered by a Manycast client.

* A Manycast client probes the multicast / broadcast address to discover
Manycast servers.

* Once the Manycast client locates an eligible Manycast server a unicast
association is established.

Steve Kostecke <kostecke at ntp.isc.org>
NTP Public Services Project - http://ntp.isc.org/

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