[Guy Harris <gharris@xxxxxxxxxxxx>]

On Sun, Dec 24, 2000 at 03:06:45PM +0800, jonathan wrote:
>  so please do take a look and could someone please explain the option
> field. (which I cannot account for even when using the hex output for
> ethereal).

Which version of Ethereal are you using?  (Either run "ethereal -v" from
the command line, or select "About" from the "Help" menu.)

It is possible that versions from 0.8.3 (when support for dissecting
TFTP options was added) to 0.8.13 could, when parsing options, run past
the end of the buffer, pick up whatever random junk happens to be in
memory after the end of the packet data, and display it as the value of
an option.

In 0.8.14, however, the TFTP dissector was changed to use tvbuffs, so it
should throw an exception if it tries to do that, and there should be a
"Short Frame" or "Malformed Frame" error if that happens.