RE: [Ethereal-users] RE: "Malformed" ASF RMCP ACK packets

["Rob Swindell" <swindell@xxxxxxxxxxxx>]

> Hi,
> 
> > Re-sending due to lack of acknowledgement/response:
> > 
> > Ethereal (v0.10.4) is reporting received ASF RMCP ACK packets
> > as being "malformed" when they appear to be perfectly 
> valid. Example:
> > 
> > 0000  00 0f 1f d7 cd 46 00 b0  d0 21 00 48 08 00 45 00   
> > 0010  00 20 3d 9a 00 00 20 11  fd 44 ac 10 01 ef ac 10   
> > 0020  05 df 02 6f 02 6e 00 0c  93 84 06 00 01 86 00 00   
> > 0030  00 00 00 00 00 00 00 00  00 00 00 00               
> > 
> > This is an ASF RMCP ACK of an ASF RMCP Capabilities Request packet.
> > 
> > I can only guess that Ethereal is assuming that ASF RMCP ACK
> > packets are supposed to include a data block, when in fact 
> they do not
> > (see section 3.2.2.1 Note 1 in the ASF Specification).
> > 
> > Perhaps someone on the Ethereal development team can point
> > out exactly what it is that Ethereal is expecting, but not 
> finding, in
> > this packet?
> 
> There is a development list you might use if you are trying 
> specifically to contact developers -althouth I believe most 
> of them subscribe to this also-.
> 
> I suppose nobody can immediately derive your problem from 
> your description, so if you attach a trace -the trace file 
> with the packet, not only the hex dump- I can try and have a 
> look at it; with the disclaimer that I don't know a bit 
> about ASF, I can only try and find the place where the 
> program is expecting 
> something it does not find. If you add a pointer to the ASF 
> Specification it would probably also help.

I attached a trace file that demonstrates this problem (a valid RMCP ack packet reported as "malformed" by Ethereal).

Here's a link to the ASF specification:

http://www.dmtf.org/standards/documents/ASF/DSP0136.pdf

-Rob

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