Re: Metamako DLT Request

[Guy Harris <gharris () sonic net>]

On Jul 23, 2018, at 6:36 PM, David Mirabito <davidm () metamako com> wrote:

> We'd like to request a new DLT_ value for Metamako's packet capture trailer
> that is generated by our MetaWatch network application.
>
>      https://www.metamako.com/applications/metawatch-app.html
>
> It is a variable length data trailer, appended immediately after an
> original Ethernet Payload. It is backwards-compatible with DLT_EN10MB but
> adds additional fields after the original frame payload until the
> end-of-frame marker.
>
> We were thinking something like this
>
>    LINKTYPE_METAMAKO_TRAILER --> DLT_METAMAKO_TRAILER
>
> Is there anything in particular that you require?

A detailed description of the format of the trailer.

Presumably, for Ethernet packets with a type field, the trailer can't be found until the payload is dissected, because 
there's no other way to determine how large the payload is.

Also, presumably, the trailer comes after any padding, and there's no FCS in these packets.
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