Re: decode MPLS-contained packets?

[Gert Doering via tcpdump-workers <tcpdump-workers () lists tcpdump org>]

> --- Begin Message ---
>
>
> From: Gert Doering <gert () greenie muc de>
>
> Date: Tue, 5 May 2020 21:44:00 +0200
>
> Hi,
>
> On Tue, May 05, 2020 at 08:47:04PM +0200, Francois-Xavier Le Bail wrote:
> > > So, given that the first 16 bits are "4 bit always 0, and 12 bits
> > > reserved-must-be-set-to-0", using these as heuristics for "if two 0-bytes
> > > are following the MPLS headers, it's a control word, so we skip 4 bytes
> > > and the rest is a regular Ethernet packet" should work.
> >
> > We should print "PW Ethernet Control Word" and the "Sequence Number", 2 last 2 octets of the 4.
> > Like:
> > PW Ethernet Control Word, Sequence Number xxx
>
> I think we should only print this if "-v" is given.  Most of the time, 
> both control word and sequence number are of little interest.
>
> I really like tcpdump's very compact "only the most relevant info" output
> format (by default).
>
> gert
> -- 
> "If was one thing all people took for granted, was conviction that if you 
>  feed honest figures into a computer, honest figures come out. Never doubted 
>  it myself till I met a computer with a sense of humor."
>                              Robert A. Heinlein, The Moon is a Harsh Mistress
>
> Gert Doering - Munich, Germany                             gert () greenie muc de
>
> --- End Message ---
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