[ntp:hackers] Receiving smeared time

Harlan Stenn stenn at ntp.org
Tue Jun 30 10:19:24 UTC 2015


Miroslav Lichvar writes:
> On Tue, Jun 30, 2015 at 12:17:20AM -0400, Danny Mayer wrote:
> > The real problem here is that the Refid is NOT an IP address. From the
> > RFC it is meant to be formed from an IP address but any 32-bit number
> > will do. Furthermore the reference implementation makes the mistake of
> > setting the Refid based on the IP address from which it is sent instead
> > of setting up and using the same Refid for ALL interfaces and addresses.
> 
> The trouble is that currently the refid is generated on clients,
> there is no way for a server to tell its clients its refid. The
> clients generate it from the IP address of the server because there is
> no other information that would be stable and unique to the server.

Huh?  An S1 sends its refid in the packet to the client.  An S2+
sends the refid of its system peer in the packets it originates.

H


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