[ntp:questions] Stratum 1 configuration hints

Unruh unruh-spam at physics.ubc.ca
Thu Nov 12 23:35:31 UTC 2009

shane-dated-2009 at csy.ca writes:

>Hey all,

>I am running a stratum 1 server (Garmin 18 LVC) on Linux and think I have it
>humming pretty smoothly at this point. Offset around 8 US and jitter 1-2US.
>The GPS is the only clock source though and I'm wondering whether a stratum
>1 server should peer with others. If so, do I need to go hunt down stratum 1
>servers willing to peer or can I use otherwise unconnected stratum 2-3
>servers such as are in the NTP pool? At stratum 1, should peer or server be

Why, except as a backup, and as a backup you can use a higher stratum
clock, making sure that it is not getting its time from you even
indirectly (you do not want loops).

>This is very much a hobby project for me, not a serious thing though I am
>perfectly willing to add to the public ntp server list but I don't think
>this rig would qualify to peer with the nist or usno servers or any such
>thing so I'm hoping stratum 1 peering isn't necessary.

Use pool.ntp.org as a backup for your gps. 

You will only get 100s of usec to ms accuracy from those backups, but
then they are backups. YOu could also buy another 5 GPS18s to use as
backup if you really wanted to make sure you get usec time at all times. 


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