linux:netzwerk:ntp
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NTP
Ausgabe von ntpq -p
remote – The remote peer or server being synced to. “LOCAL” is this local host (included in case there are no remote peers or servers available); refid – Where or what the remote peer or server is itself synchronised to; st – The remote peer or server Stratum t – Type (u: unicast or manycast client, b: broadcast or multicast client, l: local reference clock, s: symmetric peer, A: manycast server, B: broadcast server, M: multicast server, see “Automatic Server Discovery“); when – When last polled (seconds ago, “h” hours ago, or “d” days ago); poll – Polling frequency: rfc5905 suggests this ranges in NTPv4 from 4 (16s) to 17 (36h) (log2 seconds), however observation suggests the actual displayed value is seconds for a much smaller range of 64 (26) to 1024 (210) seconds; reach – An 8-bit left-shift shift register value recording polls (bit set = successful, bit reset = fail) displayed in octal; delay – Round trip communication delay to the remote peer or server (milliseconds); offset – Mean offset (phase) in the times reported between this local host and the remote peer or server (RMS, milliseconds); jitter – Mean deviation (jitter) in the time reported for that remote peer or server (RMS of difference of multiple time samples, milliseconds);
The first character displayed in the table (Select Field tally code) is a state flag (see Peer Status Word) that follows the sequence ” “, “x”, “-”, “#”, “+”, “*”, “o”:
” ” – No state indicated for:
non-communicating remote machines,
“LOCAL” for this local host,
(unutilised) high stratum servers,
remote machines that are themselves using this host as their synchronisation reference;
“x” – Out of tolerance, do not use (discarded by intersection algorithm);
“-” – Out of tolerance, do not use (discarded by the cluster algorithm);
“#” – Good remote peer or server but not utilised (not among the first six peers sorted by synchronization distance, ready as a backup source);
“+” – Good and a preferred remote peer or server (included by the combine algorithm);
“*” – The remote peer or server presently used as the primary reference;
“o” – PPS peer (when the prefer peer is valid). The actual system synchronization is derived from a pulse-per-second (PPS) signal, either indirectly via the PPS reference clock driver or directly via kernel interface.
The refid can have the status values: An IP address – The IP address of a remote peer or server; .LOCL. – This local host (a place marker at the lowest stratum included in case there are no remote peers or servers available); .PPS. – “Pulse Per Second” from a time standard; .IRIG. – Inter-Range Instrumentation Group time code; .ACTS. – American NIST time standard telephone modem; .NIST. – American NIST time standard telephone modem; .PTB. – German PTB time standard telephone modem; .USNO. – American USNO time standard telephone modem; .CHU. – CHU (HF, Ottawa, ON, Canada) time standard radio receiver; .DCFa. – DCF77 (LF, Mainflingen, Germany) time standard radio receiver; .HBG. – HBG (LF Prangins, Switzerland) time standard radio receiver; .JJY. – JJY (LF Fukushima, Japan) time standard radio receiver; .LORC. – LORAN-C station (MF) time standard radio receiver. Note, no longer operational (superseded by eLORAN); .MSF. – MSF (LF, Anthorn, Great Britain) time standard radio receiver; .TDF. – TDF (MF, Allouis, France) time standard radio receiver; .WWV. – WWV (HF, Ft. Collins, CO, America) time standard radio receiver; .WWVB. – WWVB (LF, Ft. Collins, CO, America) time standard radio receiver; .WWVH. – WWVH (HF, Kauai, HI, America) time standard radio receiver; .GOES. – American Geosynchronous Orbit Environment Satellite; .GPS. – American GPS; .GAL. – Galileo European GNSS; .ACST. – manycast server; .AUTH. – authentication error; .AUTO. – Autokey sequence error; .BCST. – broadcast server; .CRYPT. – Autokey protocol error; .DENY. – access denied by server; .INIT. – association initialized; .MCST. – multicast server; .RATE. – (polling) rate exceeded; .TIME. – association timeout; .STEP. – step time change, the offset is less than the panic threshold (1000ms) but greater than the step threshold (125ms)
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