Re: [Linuxptp-users] Grandmaster Auto-Negotiation and Reconfiguration of phc2sys to ptp4l Synchronization

[Miroslav L. <mli...@re...>]

On Mon, Aug 17, 2015 at 01:27:01PM +0000, Harold Lapprich wrote:
> So let me see if I understand you correctly, if the system of say 6 devices on a local network are all started with 'timemaster' and the GrandMaster is removed (i.e., the device has to be serviced or fails) then 'timemaster' in the background will detect this and restart everything and the device that becomes the GrandMaster will begin providing clock updates to NTP or receiving clock correction from NTP?

No, timemaster is currently PTP slave only. It starts ptp4l with the
slaveOnly option, so it can't become a master. With current phc2sys it
wouldn't work anyway. It would need to be modified to switch between
two servos, NTP SHM when the PTP clock is synchronized and a real
servo when the system clock is the source.

> In the network configuration I am looking at creating each system will be capable of being the NTP server (ntpd demon can be started) and then using 'timemaster' to create the end-to-end configuration for precise timing.

As the linuxptp code currently stands, I think you will need to keep
ptp4l/phc2sys in control of the system clock and configure
ntpd/chronyd to just serve the local time with the LOCAL driver/local
stratum option with no other time sources listed in the config.

For example:
ptp4l -i eth0
phc2sys -a -r -r
chronyd 'local stratum 1' 'allow'

-- 
Miroslav Lichvar