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Conference lassie::ucx

Title:DEC TCP/IP Services for OpenVMS
Notice:Note 2-SSB Kits, 3-FT Kits, 4-Patch Info, 7-QAR System
Moderator:ucxaxp.ucx.lkg.dec.com::TIBBERT
Created:Thu Nov 17 1994
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:5568
Total number of notes:21492

5247.0. "General NTP Questions" by BSS::G_MCINTOSH (Touch Not the Cat, Bot the Glove) Wed Feb 19 1997 17:59

    
    Some general NTP questions:
    
    * how often is the server polled?                                       
    
    * how does ntp handle daylight saving time?                             
      immediately?  gradually?                                        
    
    * is there a range or value for the time being off from the
      time server?  What happens if it's exceeded?
    
    Thanks......Glenn
T.RTitleUserPersonal
Name		DateLines
5247.1CSC32::H_SOReboot twice 'n call me in the mornin'Wed Feb 19 1997 22:4821
    I talked to the customer that Glenn was working with and came up 
    with these answers, please let me know if I'm off base:
    
    <       * how often is the server polled?
    According to the log files, 35 seconds is the minimum, and the synch
    can occur as little as 35 seconds apart.  Customer also saw this with
    packet trace.
    
    <       * how does ntp handle daylight saving time?
    <               immediately?  gradually?
    If the server's clock is set immediately, then the clients' clocks
    are also set almost immediately as soon as synch occurs.  Since on VMS,
    system manager has to set the clock forward/back manually, he could
    gradually change the clock on the server source.
    
    <       * is there a range or value for being off from the
    <               time server?  What happens if it's exceeded.
    None I'm aware of, but there has been some talk about it in the notes
    about being off for more than 24 hours...
    
    Jay
5247.2don't overestimate NTP's capabilities...UTRTSC::KNOPPERSOswald KnoppersThu Feb 20 1997 08:0318
>    <       * how does ntp handle daylight saving time?
>    <               immediately?  gradually?
>    If the server's clock is set immediately, then the clients' clocks
>    are also set almost immediately as soon as synch occurs.  Since on VMS,
>    system manager has to set the clock forward/back manually, he could
>    gradually change the clock on the server source.

I don't think this is true. As far as I know, the timestamps put on the
wire are all in UTC. This means there is no change when DST happens. DTS is
only meaningful for the local node (different nodes in your network can be
in different timezones).

As far as I know, the UCX NTP implementation doesn't handle DST. You need
operator intervention to change the time.

Regards,

Oswald