[Linuxptp-users] Configuration for boundary clock with on two-port NIC

[Nils F. <nil...@sr...>]

Hello everyone!

I am looking for help configuring a 2 port NIC as boundary clock. The 
PTP sync is coming in on one port and I want to forward it to the other 
one. I got something working but the sync is not as good as I expected. 
The sync on the receiving port looks like this:

ptp4l[775]: [325626.344]: rms    7 max   13 freq -33893 +/-  11 delay   
170 +/-   1
ptp4l[775]: [325626.344]: rms    7 max   13 freq -33893 +/-  11 delay   
170 +/-   1
ptp4l[775]: [325627.469]: rms    5 max   11 freq -33891 +/-   9 delay   
170 +/-   1
ptp4l[775]: [325627.469]: rms    5 max   11 freq -33891 +/-   9 delay   
170 +/-   1
ptp4l[775]: [325628.594]: rms    4 max    9 freq -33893 +/-   6 delay   
169 +/-   1
ptp4l[775]: [325628.594]: rms    4 max    9 freq -33893 +/-   6 delay   
169 +/-   1
ptp4l[775]: [325629.718]: rms    9 max   14 freq -33884 +/-  14 delay   
170 +/-   1
ptp4l[775]: [325629.718]: rms    9 max   14 freq -33884 +/-  14 delay   
170 +/-   1
ptp4l[775]: [325630.843]: rms    3 max    5 freq -33886 +/-   5 delay   
170 +/-   1
ptp4l[775]: [325630.843]: rms    3 max    5 freq -33886 +/-   5 delay   
170 +/-   1

Unfortunately, the sync on the server receiving the sync from the BC 
looks like this:

ptp4l[3297.441]: master offset         42 s2 freq   +9338 path 
delay       319
ptp4l[3298.441]: master offset        -10 s2 freq   +9298 path 
delay       319
ptp4l[3299.441]: master offset         19 s2 freq   +9324 path 
delay       319
ptp4l[3300.441]: master offset        -23 s2 freq   +9288 path 
delay       321
ptp4l[3301.441]: master offset         11 s2 freq   +9315 path 
delay       321
ptp4l[3302.441]: master offset        -22 s2 freq   +9285 path 
delay       322
ptp4l[3303.441]: master offset          6 s2 freq   +9307 path 
delay       322

Is there a way to improve the configuration? I found the 
boundary_clock_jbod parameter but setting it to 1 didn't improve the 
sync. Can someone provide a configuration for a simple BC setup with one 
two-port NIC? What is the sync quality I can expect? Any help is 
appreciated! Thanks in advance!

Best regards
Nils