Ethereal-users: Re: [Ethereal-users] TCP "Data" ?

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From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Wed, 19 Nov 2003 12:47:47 -0800

On Nov 19, 2003, at 12:14 PM, Tony Scarola wrote:

I am attempting my first Ethereal 0.9.16 packet capture and analysis(660,865
frames). Upon performing the protocol analysis, I have come across the
protocol "Data" (Frame/Ethernet/Internet Protocol/Transmission Control
Protocol/Data) as shown within "Protocol Hierarchy Statistics" screen, and cannot find any information as to its definition. I assume it refers to TCP data that does not match the "known" ports that Ethereal understands, but
need to be sure.

It refers to anything that a given dissector, such as the TCP dissector, doesn't find a dissector to handle, and dissects it as "Data" instead. If it's under "Transmission Control Protocol", it refers to TCP payload for traffic that isn't to or from a known port, isn't matched by a heuristic dissector that runs atop TCP (ONC RPC, DCE RPC, etc.), and isn't part of a conversation set up by another protocol (e.g., something set up as RTP or RTCP by RTSP or SIP/SDP).

Is there any way to build a filter to show only this TCP Data as described
above?

"tcp && data" should work - although that'd also show packets if the protocol running atop TCP *itself* had payload that it handed to a subdissector, but couldn't find a subdissector and dissected it as "Data".