Ethereal-users: Re: [Ethereal-users] Incorrect Frame Length and Missing FCS - Attachments
On Jun 23, 2004, at 20:18, Russell Teague wrote:
I'm working with a proprietary Ethernet traffic generator/analyzer and
Ethereal consistently reports a shorter length (by 4 bytes) and doesn't
display the FCS. Is there an option that I'm missing or something? I
know
the fcs is present and that the frame is 4 bytes longer than reported
because I've used two different analyzers to verify this.
Typically, the system's network device handlers do not provide the FCS
to applications; that is normally stripped off by the device and
effectively dropped. The only system I know of for sure that provides
this facility (under program control only) is AIX 4.x, and not all
drivers do this.
If the 4 missing bytes include the FCS, that is the reason (the FCS
isn't present). Without the FCS the minimum frame size is 64 bytes.
I've included a
pdf printout of one of the packets as seen in Agilent's Advisor, I've
also
included a capture of the packet in question. Any help with this will
be
greatly appreciated.
If you can, in the future, please stick to ASCII (no HTML, no PDFs).
That makes life easier for all of us, on widely varying systems, to
read mail with a minimum of hassle.
Hope that helps.
Regards,
Justin
--
Justin C. Walker, Curmudgeon-At-Large *
Institute for General Semantics | "Weaseling out of things is
what
| separates us from the animals.
| Well, except the weasel."
| - Homer J Simpson
*--------------------------------------*-------------------------------*
