[ntp:questions] Re: Reference Identifier

John Hay jhay at dolphin.icomtek.csir.co.za
Tue Aug 5 08:00:04 UTC 2003


Morpheus <spam at world.com> wrote:
:> Again, see RFC-1305 for detailed explanation or, for that matter,
:> RFC-2030 which you quote. The IPv4 reference identifier is exactly as
:> specified therein. The IPv6 reference identifier has been modified. See
:> http://www.eecis.udel.edu/~mills/database/rfc/rfc-xxxx.pdf.

: for a secondary server the RefID is an IP address: YES/NO? i'd press Y...

Maybe just something that might not be obvious if you think only about
your own network. The fact that you sync to a secondary server using
IPv4 or IPv6, does not imply that it gets its time the same way. So you
might use IPv4 to get time from a secondary server, but it might get
time from its upstream using IPv6. In this case the secondary server
acts as an IPv6 secondary server and the REFID that you get will be
part of the MD5 hash. To keep it interesting, the secondary server
might have some IPv4 and some IPv6 upstream servers, in which case
even though you use IPv4 to get time from it, you might sometimes
get an IPv4 REFID and sometimes an IPv6 style REFID. At the end it
is better not to try and do clever things with the REFID, but rather
just use it as a 32 bit value used to detect synchronization loops.

John



More information about the questions mailing list