NTP seems to be the standard in time synchronization in networks where the NTP server is known, however I'm looking for a solution that would work with zero conf or avahi. In a way that devices recently added to the network could automatically discover the clock MASTER and source date and time from them, optionally they could become the master themselves.
I know that PTP works in that way, but it's made to share very precise timestamps, not time and date. Do you know of any solutions that would work in this case?