On Thursday 02 September 2004 05:01 am, Constant Brouerius van Nidek wrote:
Right now I get a star for darkstar.sanet and after a ten minutes I also got a plus sign in front of ns01.deu.edu.tr What does the plus mean? Just before I wanted to send this email my1.doubleukay also got a plus in front.
202.180.0.71 .STEP. 16 u - 128 0 0.000 0.000 4000.00 my1.doubleukay. 164.67.62.194 2 u 49 64 107 1022.56 -58.216 1.617 +ns01.deu.edu.tr 195.113.144.201 2 u 59 64 177 915.493 -0.621 13.994 *darkstar.sanet. 212.82.32.15 2 u 56 64 177 840.781 -17.948 40.706
An asterisk * in the first column marks the reference time source which is currently preferred by the NTP daemon, the + character marks high quality candidates for the reference time which could be used if the currently selected reference time source should become unavailable. The column remote displays the IP address or the host name of the reference time source, where LOCAL refers to the local clock. The refid shows the type of the reference clock, where e.g. LOCAL or LCL refers to the local clockagain, .DCFa. refers to a standard DCF77 time source, and .PPS. indicates that the reference clock is disciplined by a hardware pulse-per-second signal. Other identifiers are possible, depending on the type of the reference clock. The column st reflects the stratum number of the reference time source. In the example above, the local clock has stratum 12, the remote time server at 172.16.3.103 has stratum 1 which is the best you can see across the network, and the local radio clock has stratum 0, so the radio clock is currently being preferred. Every time a when count reaches the poll number in the same line, the NTP daemon queries the time from the corresponding time source and resets the when count to 0. The query results of each polling cycle are filtered and used as a measure for the clock's quality and reachability. The column reach shows if a reference time source could be reached at the last polling intervals, i.e. data could be read from the reference time source, and the reference time source was synchronized. The value must be interpreted as an 8 bit shift register whose contents is displayed as octal values. If the NTP daemon has just started, the value is 0. Each time a query was successful a '1' is shifted in from the right, so after the daemon has been started the sequence of reach numbers 0, 1, 3, 7, 17, 37, 77, 177, 377. The maximum value 377 means that the eight last queries were completed successfully. The NTP daemon must have reached a reference time source several times (reach not 0) before it selects a preferred time source and puts an asterisk in the first column. The columns delay, offset and jitter show some timing values which are derived from the query results. In some versions of ntpq the last column is labeled disp (for dispersion) instead of jitter. All values are in in milliseconds. The delay value is derived from the roundtrip time of the queries. The offset value shows the difference between the reference time and the system clock. The jitter value indicates the magnitude of jitter between several time queries. -- _____________________________________ John Andersen