[ntp:questions] Re: Reference Identifier

Morpheus spam at world.com
Mon Aug 4 08:24:46 UTC 2003


> Please see the spec again and note the difference between the reference
> identifier and reference timestamp fields.

i'm really sorry but i don't understand... :(
in the specs, RFC 2030 SNTPv4, we find:

*Reference Timestamp: this is the time at which the local clock was set or
corrected, in 64-bit timestamp format.

-> this means that server synchronize with "something" (via another NTP
server or an external reference) and if it has to correct its clock that
was the time when it indeed corrects its clock: am i wrong?

*Reference Identifier: NTP server v3-4 stratum 0-1 it is an ASCII string;
NTPv3 secondary server, it is the IPv4 address of the reference source;
###NTPv4 secondary server it is the low order 32 bit of the latest transmit
timestamp of the reference source###

-> the ###...### part is the one which i don't understand... are you talking
about the second half of the NTP timestamp (ie the fractional part)? if so,
but of which timestamp? the last update of the local (server) clock?

>From what i've understood, Ref ID is not a timestamp but is just a part of a
time stamp (which??) and analizing the packets it is NOT the integer part
of a time stamp (seconds) because of the first byte of the now-day NTP
timestamp is 0xc2 which is not the first byte of the RefID (which is varing
very fast) so i suppose this is the fractional part (fractions of seconds)
of the last update of the local (server) clock due to synchonization with
its reference source. is it right?

Thanks for your time and help!



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