Re: [Linuxptp-users] ptp forwarding

[Maxime L. <max...@gm...>]

Thank you very much,

so, if I read the doc correctly, since I want my CLOCK_REALTIME synched too
(by eth0 in my use case) I use

        ptp4l -i eth0 -i eth1 -i eth2 --boundary_clock_jbod=1
        phc2sys -a -r

... and all devices should use HW timestamping. I understand that I can not
use the -O -37 anymore, so how will I get UTC time on my CLOCK_REALTIME?

Can/should I force eth0 to be slaveOnly (this one is to be mastered by my
TimeServer on subnet 192,168..0.x), or should I let it it figure all this
out automatically?


Again, thanks a lot for your help.

Maxime


On Wed, Oct 3, 2018 at 4:05 PM Richard Cochran <ric...@gm...>
wrote:

> On Wed, Oct 03, 2018 at 03:54:59PM +0000, Keller, Jacob E wrote:
> > If I recall correctly, you need to use boundary_clock_jbod=1 while also
> setting all three interfaces, in a single invocation of ptp4l, and ofcourse
> they all must report hardware timestamping capability.
> >
> > I am not sure about phc2sys configuration though.
>
> Right, so for JBOD mode you would use:
>
>         ptp4l -i eth0 -i eth1 -i eth2 --boundary_clock_jbod=1
>         phc2sys -a
>
> From the ptp4l man page:
>
>        boundary_clock_jbod
>               When  running  as  a boundary clock (that is, when more than
> one
>               network interface is configured), ptp4l performs a sanity
> check
>               to make sure that all of the ports share the same hardware
> clock
>               device. This option allows ptp4l to work  as  a  boundary
> clock
>               using  "just  a  bunch  of devices" that are not
> synchronized to
>               each other. For this mode, the collection of clocks must be
> syn‐
>               chronized  by  an  external  program,  for example
> phc2sys(8) in
>               "automatic" mode.  The default is 0 (disabled).
>
> From the phc2sys man page:
>
>        With the -a option, the clocks to synchronize are fetched from the
> run‐
>        ning  ptp4l  daemon  and the direction of synchronization
> automatically
>        follows changes of the PTP port states.
>
>        ...
>
>        -a     Read  the  clocks  to  synchronize from running ptp4l and
> follow
>               changes in the port states, adjusting the synchronization
> direc‐
>               tion  automatically.  The  system  clock (CLOCK_REALTIME) is
> not
>               synchronized, unless the -r option is also specified.
>
> HTH,
> Richard
>