Help resolving chronyd issues

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I am having an issue resolving a chronyd issue on Rhel 7. The server should sync with a Windows 2012 R2 configured as an ntp server.

I have a Rhel 6.9 running chronyd which does this. My Rhel 7.4 running chronyd does not.

The issue is not dns, since the Rhel 7.4 resolves the name of the server. It can also tell how far off from the clock it is, so it is getting feedback from the server.

From what I have read, I don't know how the values get established in the /var/lib/chrony/drift file.

I have tried different values of makestep, to try and get chronyd to set the time at boot.

The firewall has the ntp service enabled.

I have been unable to conclusively determine if the issue is with the Rhel 7.4 or the Windows Server.

I have attached some config file extracts from the various systems.

Any help would be greatly appreciated. I've been struggling with this for a while.

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Hi David,

I am not sure I understand exactly what is the problem is in comparison to your RHEL 7.4 server.

Firstly, a single reference clock is not the best practice, and it being a Windows server even more.

If you have any choice, use some of the routers/switches for that role, if you do not have any other type of dedicated appliances.

Secondly, you are using Windows 2012 server to the best of its "abilities".

You are not missing a single beat , hence 377 "Reach" status.

"^*" says that you are synchronized with server at IP address 172.16.13.100 (Windows 2012 server).

The "Last sample" offset between the local clock and the source at the last measurement is OK too (in microseconds).

I would suggest to try "iburst" option in your config. If this option is set, the interval between the first four polls will be 2 seconds instead of minpoll. This is useful to quickly get the first update of the clock after chronyd is started.

Regards,

Dusan Baljevic (amateur radio VK2COT)

Hi David, also examine this RH solution https://access.redhat.com/solutions/1259943. I agree with Dusan above, it's better to have more than one reference clock (see next link too), that article says to have more than 2 sources.

Also, please examine this RH solution https://access.redhat.com/solutions/58025

Additional background on the driftfile is here https://chrony.tuxfamily.org/manual.html and also here (red hat documentation)

Thank you to both of you for your comments. This is a disconnected network. I have no external connectivity outside of the local LAN. That is the reason I was using the Windows Server. I will review the list of articles both of you suggested, and see if I can get it working.

It is only the Rhel 7.4 having issues. The Rhel 6.9 is happy as a clam.

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