I've posted an updated tarball that fixes some build issues and limits re-resolving the same hostname to once every four hours. I'm expecting to change that to 24 hours later, as it prevents re-resolving a hostname with a single IP every 11 minutes or so (assuming poll 6/64s) when the IP address is not working. So far no feedback has been offered, so please consider giving it a whirl. If you want an easy test to see the re-resolution happening use "server reresolv.davehart.net".
Note this does not have the code to refine pool servers as in the 3792 tarball. Find it at https://people.ntp.org/hart/ntp-stable-617-2.tar.gz Thanks, Dave Hart On Fri, 14 Jul 2023 at 16:52, Dave Hart <h...@ntp.org> wrote: > For at least 17 years folks have asked for ntpd to re-resolve hostnames > given in ntp.conf. For the limited case of "pool", that's been done for > over a decade. Generalizing that to all server/peer hostnames hasn't > happened until now. > > Ideally this would happen even when the IP address ntpd resolved still > provides NTP service, but I haven't done that part yet. I have a test > tarball which re-resolves hostnames of servers which are no longer > responding on the previously-resolved IP address. I would very much > appreciate a bit of testing before this code is integrated into the > distribution. Because re-resolution happens only when the server is no > longer responsive, it will be easiest to test using a hostname in > /etc/hosts or in a DNS domain you control, so that you can point it to a > hostname which doesn't work initially, then change the hosts file or DNS to > point to a hostname that does work. In the case of DNS, you could also > have several A or AAAA records for one name where only one actually serves > NTP, and with a little luck you'll get one of the non-working IPs first. > I'm not sure if that can be done with the hosts file. > > Feedback is welcome via https://bugs.ntp.org, or to > questions@lists.ntp.org, or directly to me at daveh...@gmail.com or > h...@ntp.org. Find it at: > > https://people.nwtime.org/hart/ntp-stable-617.tar.gz > > Thanks in advance, > Dave Hart >
