Re: [v6ops] draft-elkins-6man-ipv6-diagnostic-header (Was: draft minutes ietf 81, 3 meetings...)

[Keith Moore <[e-mail]>]

On Aug 14, 2011, at 1:03 PM, Carlos Pignataro wrote:

> I believe there was one further point raised in regards to
> draft-elkins-6man-ipv6-diagnostic-header (though I don't recall if it
> was at the mike by Andrew Y., in a corridor, or only in my head): the
> Heisenbug principle -- if this is used in debugging (and diagnostics),
> the issue being studied or attempted to reproduce alters its behavior or
> goes away when modifying the packet (like compiling with different -o).

Yes, this can happen.  But that doesn't mean the mechanism is useless.   It just means that the potential error introduced by the mechanism needs to be taken into account when making measurements based on it.

(Just as Heisenberg's principle doesn't prevent us from measuring either present position or future momentum of a particle.  It just says that there's a limit to the precision with which both can be measured simultaneously.)

I basically think that it's a potentially good idea.  The real trick is understanding how to implement it in hosts so that it can be turned on when appropriate without affecting (much) the applications generating the affected traffic.

Keith