[Linuxptp-users] How to run multiple instances of ptp4l

[Rich S. <sch...@gm...>]

I am attempting to run multiple instances of ptp4l on a PTP slave. The idea
is that I have an Intel i350-T4 NIC and I want each port to sync to a
different GrandMaster.  (The slave is an NTP stratum 1 server which would
sync to multiple GrandMasters, where each GrandMaster is in turn synced to
an independent time source, like USNO Master Clock1, MC2, MC3...providing
redundancy for NTP ).    Does this concept require linuxpp operation in
unicast mode?  For when I start the second instance of ptp4l, broadcast
mode from the GrandMaster causes PTP confusion on the slave. (Testing with
one GrandMaster feeding each of two PHCs on the slave.)
So I imagine that unicast associations would prevent the slave's ports from
grabbing packets intended for neighboring NICs.
An alternative would be to VLAN the individual ports/GrandMasters, but at
the moment I am testing this using only one GrandMaster for multiple slave
ports.

Thank you,
Rich Schmidt, CTR
US Naval Observatory
Washington, DC