On 12/02/14 14:35, Nathan Ward wrote: (stuff) I think what I'm trying to get to is: (1) Time synchronisation to at least second resolution (and preferably much better) is Important. (2) Service providers should provide a robust stratum 2 NTP service to customers. (3) They don't need to do stratum 1. There are reliable, professionally managed NTP services out there available for use. (4) If you operate a local stratum 1 server, you should run a customer facing stratum 2 service, feeding from both local and remote stratum 1 servers. (5) Using NTP pools to synchronise customer facing NTP services is a Very Bad Idea. (6) Using one's service provider's NTP service should be vastly more robust than using the NTP pools. If it's not, that represents a failure on the part of the provider. As I think about this, I'm starting to regard NTP pools as an attractive nuisance - the simplicity of using the pools (and the increasing use of them in preconfigured devices) means that an important service is being provided on unstable systems, often run by amateur operators on a grace and favour basis. That does not bode well for the general stability of applications that require good time. -- don