Larry Jones wrote:
> -----Original Message-----
[smc] [...]
> > 4) Automatic NTP correction of the system time (pretty common in the
> Unix
> > server world).
> > (Under Windows 2000 it is possible for all the machines in a given
> > domain to periodically
> > sync their clocks with the PDC).
>
> NTP never sets the clock backwards (see 2, above).
>
[smc] Are you sure? I thought I remembered differently,
so I tried to check..., I found RFC 1305...(is that the right
one?)
From the RFC 1305, "Network Time Protocol (Version
3) Specification, Implementation and Analysis":
"[...] In practice, the necessity to perform a step change
is rare and usually occurs when the local host or reference
source is rebooted, for example. This is fortunate, since
step changes can result in the local clock apparently
running backward, as well as incorrect delay and offset
measurements of the synchronization mechanism itself.[...]"
Apparently a step change in the clock is done by
NTP if the clock is off as measured against the reference
clock by more than "CLOCK.MAX", but I don't know
what value CLOCK.MAX has... (seem to remember 128ms,
but that seems pretty low.).
-- steve
