[Linuxptp-users] ptp4l slave behind a BC reports GM as master clock

[Li, B. <bao...@in...>]

Hi, all

I have a PTP setup as below:
+--------+       +--------+       +--------+
|   GM   | ----- |   BC   | ----- |  Slave |
+--------+       +--------+       +--------+

GM is a GPS driven 1588 time server, BC is a switch (summit x670-g2 from extreme networks), slave is common linux server with intel x710 Ethernet adapter.



The ptp4l slave reports:

ptp4l[671200.670]: port 1: new foreign master 000496.fffe.a1e830-2
ptp4l[671202.670]: selected best master clock fcaf6a.fffe.ff4cff

a1e830 is the clock id of the boundary clock, and
ff4cff is the GM's clock id;

tcpdump results show the slave is synchronizing with BC directly.

Given the slave is sync with BC directly and there is no direct interaction between GM and slave, reporting ff4cff as "best master clock" seems a bit confusing.
Is it better to report like "best master clock a1e830, grand master ff4cff" or "parent port a1e830, grand master ff4cff"?

PS:
The GM and BC work in unicast and one-step mode.
The ptp4l is configured with:

1.       assume_two_step = 0 and

2.       hybrid_e2e = 1

3.       a few lines of change in process_sync to workaround the logMessagePeriod (it's 127 for unicast, which is not support by linuxptp);

Thank you.

Regards,
Baoqian