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Wireshark-dev: Re: [Wireshark-dev] “bytes on wire” vs. “bytes captured”

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Fri, 19 Jul 2019 09:48:18 -0700
On Jul 19, 2019, at 9:30 AM, Jasper Bongertz <jasper@xxxxxxxxxxxxxx> wrote:

> so if I get this right you expect to end up with a frame where length of the original
> content is less than what ends up in the pcap because meta data is added? This
> usually happens by adding a trailer to the Ethernet frame,

Not necessarily.  See the examples I gave, in which case it's done by adding a header to the frame.

> If you have a capture device that wants to write additional detail about a frame
> to the capture file you should choose pcapng instead.

Or choose a different link-layer header type, which works with pcap or pcapng, as per the examples I gave.