locked Re: Meinberg NTP at Windows startup

Bill Somerville

On 10/02/2020 15:16, John Morphet wrote:
I am running Meinberg NTP on a Windows 10 machine. It is working well except when I first start the computer in the morning. I have noticed that when I start my computer in the morning the time is usually off by about a second. If I run the restartntp.bat (shown below) from my desktop, the time gets corrected. I have copied the shortcut to the restartntp.bat file to the Windows startup folder. I thought that would adjust my time every time I started the computer, but it doesn't seem to work. Does anyone know how to fix this?

John, WØZI

Hi John,

the Meinberg NTP Client has to obey the rules of NTP time adjustment since it is a reference implementation of that. Time adjustments must maintain the clock ticks as monotonic and backward steps are therefore not allowed. If you PC realtime clock chip drifts ahead of time then every time the machine is powered off it's time will require slowing down to resynchronize to UTC on startup. This could take a while. The NTP protocol can be modified to cope with exactly this problm and others where large adjustment steps are required on startup. It is enabled by adding the 'iburst' attribute to one or more of the servers configured. For example my server lines in my ntp.conf file ("Start Menu->Edit NTP Configuration") look like this:

# The 'iburst' keyword speeds up initial synchronization, please check the documentation for more details!
server raspberrypi iburst prefer
server 0.uk.pool.ntp.org minpoll 11 iburst
server 1.uk.pool.ntp.org minpoll 11 iburst
server 2.uk.pool.ntp.org minpoll 11 iburst
server 3.uk.pool.ntp.org minpoll 11 iburst

Note that raspberrypi on my network is a Stratum 1 server I run synchronized to GPS satellite services using a PPS source. Most users would select just pool servers that are geographically close by, in my case the pool servers are just for backup if my local NTP server is out of action.


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