[ntp:questions] orphan mode

Richard B. Gilbert rgilbert88 at comcast.net
Wed Jun 1 20:35:38 UTC 2011

On 6/1/2011 2:42 PM, Frank Alsop wrote:
> Hi,
>     I am still confused about the proper use of the "tos orphan #" statement.
> Thanks for the replies to my last question and I have read the relevant docs at
> ntp.org.  I am pretty confident that I understand how to choose an appropriate
> orphan stratum.  However, I am not 100%, and I have been unable to convince the
> others in my group.  As a response to a previous question of mine, I was told
> that 5 is the default minimum and to set the tos orphan stratum to be greater
> than or equal to 5.  In our ntp.conf, in our stratum 2 hosts, we have "tos
> orphan 4".  The others in my group are not convinced this is a mistake, even
> with the recommendation to use a minimum of 5.  Our system has a GPS at stratum
> 1, 4 "peers" at stratum 2, a mix of clients and servers at stratum 3, with the
> highest client at stratum 5.  So, I think we should set "tos orphan 5" to adhere
> to: "A host is enabled for orphan mode using the tos orphan stratum command,
> where stratum is some stratum less than 16 and greater than any anticipated
> stratum that might occur with configured Internet time servers".  I am assuming
> that the server at stratum 4 in our system is a "configured internet time
> server".  Others in my group think that only the lowest stratum, which is our
> stratum 2 peer group, should be considered "configured internet time servers".
> Therefore, they think 4 is greater than that and we are ok.
>     So, what is the negative impact (if any) of having a "tos orphan 4" statement
> in our setup as described above?  If we had an additional server at stratum 5
> with a client at stratum 6, would we then need to set "tos orphan 6", etc.?

Why in the world are you using "Orphan Mode" when you have GPS.

My understanding of "orphan mode" is that it is intended for those 
situations in which it is impossible to use an external source of time. 
  Such situations occur when security will not allow access to an 
external NTP server.

If you have GPS, a WWV receiver, LORAN or other primary sources of time 
I don't understand why you should need or want Orphan Mode!

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