Re: [Linuxptp-devel] ptp4l wrongly takes padding bytes as TLV?

[Vincent Li X <vin...@er...>]

Sorry Miroslav! I missed you message yesterday, don't know why it ended up
in junk box.
Please see this attached FOLLOW-UP with 6 bytes of non-zero padding (64 - 14
of eth header - 44 of PDU length).  I don't know the HW NIC information.
According to 802.3, padding is done at tx/master side and could contain any
value. 


-----Original Message-----
From: Miroslav Lichvar <mli...@re...> 
Sent: Wednesday, January 30, 2019 12:55 PM
To: Vincent Li X <vin...@er...>
Cc: Jiri Benc <jb...@re...>; Mats Bergman H
<mat...@er...>; Richard Jönsson
<ric...@er...>; Lin...@li...; Anders
Selhammer <and...@er...>
Subject: Re: [Linuxptp-devel] ptp4l wrongly takes padding bytes as TLV?

On Wed, Jan 30, 2019 at 11:23:45AM +0000, Vincent Li X wrote:
> 
> Ok. Thanks Jiri!
> How do you think about our case? We run 1.6 on raw ethernet. This is a 
> normal FOLLOW-UP received with one-zero padding of 6 octets. Then 
> ptp4l take the padding as TLV.

One-zero padding sounds like beginning of another frame. I'm not sure why a
follow up message would need some special padding.

What NIC do you use? Can you show us a tcpdump -xx output? And do you see it
also on other NICs, i.e. is such packet actually transmitted by the master?

--
Miroslav Lichvar