Re: Thoughts on increasing MTUs on the internet

[Florian Weimer <fw () deneb enyo de>]

* Steven M. Bellovin:

> On Thu, 12 Apr 2007 16:12:43 +0200
> Florian Weimer <fw () deneb enyo de> wrote:
>
> > * Steven M. Bellovin:
> >
> > > A few years ago, the IETF was considering various jumbogram options.
> > > As best I recall, that was the official response from the relevant
> > > IEEE folks: "no". They're concerned with backward compatibility.  
> >
> > Gigabit ethernet has already broken backwards compatibility and is
> > essentially point-to-point, so the old compatibility concerns no
> > longer apply.  Jumbo frame opt-in could even be controlled with a
> > protocol above layer 2.

> I'm neither attacking nor defending the idea; I'm merely reporting.

I just wanted to point out that the main reason why this couldn't be
done without breaking backwards compatibility is gone (shared physical
medium with unknown and unforeseeable receiver capabilities).

> I'll also note that the IETF is very unlikely to challenge IEEE on
> this.

It's certainly unwise to do so before PMTUD works without ICMP
support. 8-)