Re: draft-ietf-v6ops-mech-v2-00.txt

[Erik Nordmark <Erik.Nordmark@sun.com>]

> >The recent changes (copied from the document):
> >   -    Clarified that the dynamic path MTU mechanism in section 3.2 is
> >        OPTIONAL but if it is implemented it should follow the rules in
> >        section 3.2.
> >
> 
> This method is susceptible to black holes (see RFC 2923).

Yes, if ICMPv4 "too big" packets are blocked by firewalls between
the encapsulator and decapsulator. 
It definitely makes sure additing warnings about this in the spec.

> >   -    Stated that implementations MAY have a knob by which the MTU can
> >        be set to larger values on a tunnel by tunnel basis, but that
> >        the default MUST be 1280 and that decapsulators need to be
> >        configured to match the encapsulaltor's MTU.
> >
> 
> This method should only be used when care is taken to avoid harmful 
> levels of
> fragmentation in the network (please see my previous note on this 
> subject). This
> needs to be clarified in the draft.

I can add warnings about this in the draft.

  Erik