To summarize for the mailinglist/Net, I can confirm the solution/explanation at the bottom
> Show us the whole thing.
You're right, sorry:
makestep 100 3
broadcast 300 192.168.110.255
The specific chrony version is:
chronyd (chrony) version 1.27-pre1 (binary distributed as part of some older Fedora distribution(F17))
> Is your dns reporting ntp.myprovider.nl
as having that address?
That hostname resolves to another address than the 192.168.178.1 entry that appeared as well in the list.
Miroslav figured it out:
> Are you using Fedora chrony package? It includes a dhclient script
> which adds (via chronyc) NTP servers obtained from DHCP. It can be
> disabled by setting "PEERNTP=no" in /etc/sysconfig/network..
Yes, this is on Fedora (17). Adding "PEERNTP=no" to /etc/sysconfig/network stopped the entry from reappearing after reboots.
(Actually it didn't but after manually deleting /var/lib/dhclient/chrony.servers.<myethdevice> it was gone from then on, I didn't try to find out exactly why the PEERNTP=no on it's own didn't seem enough)
I found the logic involved is in /etc/dhcp/dhclient.d/chrony..sh on F17.
Thanks for your help!