Wireshark-dev: Re: [Wireshark-dev] How to avoid dissection based on port defined by a different

From: Stephen Fisher <steve@xxxxxxxxxxxxxxxxxx>
Date: Thu, 16 Dec 2010 10:35:54 -0700
On Wed, Dec 15, 2010 at 09:46:34PM +0000, Christopher Maynard wrote:

> The problem I have with this is that 3503 is registered to MPLS Echo 
> so that dissector shouldn't have to be changed to essentially become a 
> heuristic one to accommodate this port-stealing protocol.

I agree that it is annoying when applications developers and 
administrators disregard best practices and use whatever port they feel 
like.  However, I'm not suggesting that we make it a full heuristic 
dissector that doesn't have an assignment and looks at all packets.  
Instead, we can just make it a "new-style" dissector that does some 
quick verification that the payload looks right and if not, kick it back 
for Wireshark to try another dissector.