[ntp:questions] Garmin GPS 18LVC Setup but questions on best way

Richard B. Gilbert rgilbert88 at comcast.net
Mon Dec 29 14:45:51 UTC 2008


George R. Kasica wrote:
>>> Since you have a GPS receiver, three internet servers should be 
>>> sufficient as backup and a sanity check for the GPS.
>> See below, now set up as recommended with three us.pool.ntp.org
>> servers but as you say it will take some time to be useful, but I
>> don't seem to be getting the NEMA data as of 1415Z 28-dec-2008.
>>
>> # ntpq -p
>>     remote           refid      st t when poll reach   delay   offset
>> jitter
>> ==============================================================================
>> GPS_NMEA(0)     .GPS.            0 l  273   16    0    0.000  -664.93
>> 0.002
>> xSHM(0)          .PPS.            0 l    7   16  227    0.000  -634.51
>> 349.893
>> eagle-local     192.168.1.7      4 u   11   64   37    0.120  -11.083
>> 0.523
>> apollo-local    192.168.1.7      3 u   18   64   37    0.224    6.685
>> 0.765
>> x64.247.17.251   129.6.15.28      2 u   12   64   37   34.158  -18.850
>> 6.764
>> +ip-72-167-54-20 204.123.2.72     2 u   13   64   37   82.722    1.031
>> 1.821
>> *caspak.cerias.p .GPS.            1 u   10   64   37   22.867    7.745
>> 10.934
>>
> 
> OK here is about 21 hours later 11Z 29 Dec-2008:
> 
> # ntpq -p
>      remote           refid      st t when poll reach   delay   offset
> jitter
> ==============================================================================
> xGPS_NMEA(0)     .GPS.            0 l    2   16  375    0.000  -722.08
> 9.115
> xSHM(0)          .PPS.            0 l    6   16  377    0.000  -722.20
> 7.892
>  eagle-local     192.168.1.7      4 u  390 1024  377    0.181   -5.629
> 4.389
>  apollo-local    192.168.1.7      4 u  410 1024  377    0.311   -2.394
> 0.299
> *got.my.mojo.net 192.5.41.41      2 u  966 1024  377   30.157   -5.166
> 0.361
> +kiri.nonexiste. 64.202.112.75    2 u  644 1024  377    9.423   -5.517
> 203.143
> +host2.kingrst.c 99.150.184.201   2 u  944 1024  377   16.221  -11.608
> 16.695
> 
> 
> still seing both of the local GPS/PPS entries as false tickers but I
> also see the offsets are huge compared to other clocks...where do I go
> from here to correct this??
> 
> ntp.conf is below:
> 
> # LinuxPPS: GPS 
> server 127.127.20.0 minpoll 4 
> fudge 127.127.20.0 flag3 1 flag2 0
>  
> # SHM: PPS filtered mean 
> server 127.127.28.0 minpoll 4 
> fudge 127.127.28.0 refid PPS flag3 1
>  
> server eagle.netwrx1.com iburst
> server apollo.netwrx1.com iburst
> server 0.us.pool.ntp.org iburst
> server 1.us.pool.ntp.org iburst
> server 2.us.pool.ntp.org iburst

Without actually being there it's difficult to say.  Clearly something 
is very wrong but exactly what is not immediately obvious, at least to 
me!  Your GPS receiver is being rejected as a falseticker!

I can't say it's because it's presenting an in correct time; that's most 
  unlikely assuming it's installed correctly and can see at least four 
satellites.




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