[ntp:questions] refid 'STC ' ? What does "STC" signify?
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Thu Jan 22 15:37:08 UTC 2009
On Jan 22, 8:57 am, Martin Burnicki <martin.burni... at meinberg.de>
wrote:
> Steve,
>
>
>
> Steve Kostecke wrote:
> > Here is the list I assembled from the current driver pages:
>
> > Driver Name Ref-Id
> > ------ --------------------------------------------------
> > --------------------
> > 1 Undisciplined Local Clock LCL
> > 2 Trak 8820 GPS Receiver GPS
> > 3 PSTI/Traconex 1020 WWV/WWVH Receiver WWV
> > 4 WWVB/GPS Receivers WWVB
> > 5 TrueTime GPS/GOES/OMEGA Receivers GPS, OMEGA, GOES
> > 6 IRIG Audio Decoder IRIG
> > 7 Radio CHU Audio Demodulator/Decoder CHU
> > 8 Generic Reference Driver PARSE
> > 9 Magnavox MX4200 GPS Receiver GPS
> > 10 Austron 2200A/2201A GPS Receivers GPS
> > 11 Arbiter 1088A/B GPS Receiver GPS
> > 12 KSI/Odetics TPRO/S IRIG Interface IRIG
> > 16 Bancomm bc635VME Time and Frequency Processor BTFP
> > 18 NIST/USNO/PTB Modem Time Services NIST
> > 19 Heath WWV/WWVH Receiver WWV
> > 20 Generic NMEA GPS Receiver GPS
> > 22 PPS Clock Discipline PPS
> > 26 Hewlett Packard 58503A GPS Receiver and HP Z3801A GPS
> > 27 Arcron MSF Receiver MSFa, MSF, DCF,
> > WWVB
> > 28 Shared memoy Driver SHM
> > 29 Trimble Palisade and Thunderbolt Receivers GPS
> > 31 Rockwell Jupiter GPS Receiver GPS
> > 32 Chrono-log K-series WWVB receiver CHRONOLOG
> > 33 Dumb Clock DUMBCLOCK
> > 34 Ultralink Clock WWVB
> > 35 Conrad parallel port radio clock PCF
> > 36 Radio WWV/H Audio Demodulator/Decoder WVf or WHf
> > 37 Forum Graphic GPS Dating station GPS
> > 38 hopf clock drivers by ATLSoft HOPF (default),
> > GPS, DCF
> > 39 hopf clock drivers by ATLSoft HOPF (default),
> > GPS, DCF
> > 40 JJY Receivers JJY
> > 42 Zyfer GPStarplus Receiver GPS
> > 43 RIPE NCC interface for Trimble Palisade RIPENCC
> > 44 NeoClock4X NEOL
>
> > As has been mentioned elsewhere in this thread, the Reference ID may be
> > set in ntp.conf.
>
> AFAIK the refid (as reported in the ntpq -p billboard) can only have up to 4
> characters since it's transported in a 32 bit value in the NTP packet, so
> it's not possible to set it e.g. to "OMEGA" or "DUMBCLOCK".
>
> Also, e.g. the parse driver sets the default refid for a refclock depending
> on the mode, e.g. "DCFp", "DCFa", or "GPS".
>
> And yes, the refid of a refclock can be set in ntp.conf, e.g.:
>
> server 172.127.8.0 mode 2 # sets the refid to "DCFa"
> fudge 172.127.8.0 refid STC # changes the refid to "STC" ;-)
>
> Martin
> --
> Martin Burnicki
>
> Meinberg Funkuhren
> Bad Pyrmont
> Germany
So other than using ntptrace to see if the refclock is reported as an
upstream server (an unlikely stratum 0) or something else, there's
really no way to know what the heck it is in reality. I can't say
that idea gives me a warm, fuzzy feeling. Correct me if I'm wrong, but
my non-caffeinated brain is telling me someone driven by a budget
could set up a server using nothing but it's LCL clock as a source but
fudge the ID to be something else. On an isolated network, there'd be
no way to detect this (assuming for this academic argument you don't
wear a reasonably accurate watch). I can imagine a group of such
servers peering with each other endlessly hunting around themselves.
If ntpd came with a "fixStupidNtpConf.ss" script, I'd feel better
about this.
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