Jared Mauch wrote:
I've found it useful on older machines (PCs with cheap clocks and oscilators) to cron ntpdate once an hour to prevent the clock from getting too far off by itself. I've found the daemon doesn't do good enough of a job to sync on it's own...
I'm also wondering, how many people are using the ntp.mcast.net messages to sync their clocks? what about providing ntp to your customers via the "ntp broadcast" command on serial links, etc..?
I run two stratum-1 servers and a few stratum-2s and I provide time via multicast (224.0.0.1), but I don't use it for my servers, except for testing and verification. I am also providing anycast ntp, and, if the belt and suspenders weren't enough, I am experimenting with manycast. That's an NTPv4 feature where the *client* sends a multicast message to an administratively-scoped group soliciting servers and then the servers respond and set up associations. From a client-configuration standpoint, it's about as convenient as multicast or anycast, but it's more accurate than multicast (since the servers set up true associations with the client) and it allows you to do NTP authentication (which I think breaks with anycast). It seems to work pretty well--the client builds up several associations as if they were all configured manually. michael