Public bug reported: In an enterprise environment where Ubuntu's NTP servers are not reachable and internal NTP servers are advertised by DHCP, chrony fails to synchronize the time.
NTP servers are correctly added to chrony sources with state 'not combined' / ^- : $ sudo chronyc sources MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^? ntp-nts-2.ps5.canonical.> 0 6 0 - +0ns[ +0ns] +/- 0ns ^- ntp-1.xxx.xx 2 6 17 10 +642us[ +642us] +/- 6477us ^- ntp-2.xxx.xx 2 6 17 10 +374us[ +374us] +/- 6321us ^- ntp-3.xxx.xx 2 6 17 11 +850us[ +850us] +/- 6927us ^? ntp-nts-3.ps5.canonical.> 0 6 0 - +0ns[ +0ns] +/- 0ns ^? ntp-nts-2.ps6.canonical.> 0 6 0 - +0ns[ +0ns] +/- 0ns ^? ntp-nts-3.ps6.canonical.> 0 6 0 - +0ns[ +0ns] +/- 0ns ^? ntp-nts-1.ps6.canonical.> 0 6 0 - +0ns[ +0ns] +/- 0ns ^? ntp-nts-1.ps5.canonical.> 0 6 0 - +0ns[ +0ns] +/- 0ns chrony logs show: chronyd[76921]: Can't synchronise: no required source in selectable sources The workaround I have found is to change `authselectmode` to `ignore` in chrony.conf (the default is `mix`). Is this the expected behavior ? Maybe https://documentation.ubuntu.com/server/how-to/networking/chrony- client/#time-sources-provided-by-dhcp-option-42 should be updated with this info. For laptops moving in and out of the enterprise network, the best would be to use Ubuntu's servers with NTS when possible and internal NTP otherwise. However, one could argue that enterprises should either have NTS or be configure NTP servers without relying on DHCP. Ubuntu 26.04 / chrony 4.8 ** Affects: chrony (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/2155165 Title: chrony does not select NTP servers from DHCP: : no required source in selectable sources To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/chrony/+bug/2155165/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
