[95967] in North American Network Operators' Group
Re: Thoughts on increasing MTUs on the internet
daemon@ATHENA.MIT.EDU (Florian Weimer)
Thu Apr 12 11:54:20 2007
From: Florian Weimer <fw@deneb.enyo.de>
To: "Steven M. Bellovin" <smb@cs.columbia.edu>
Cc: Iljitsch van Beijnum <iljitsch@muada.com>,
NANOG list <nanog@merit.edu>
Date: Thu, 12 Apr 2007 17:42:06 +0200
In-Reply-To: <20070412150554.E0FDC766657@berkshire.machshav.com> (Steven
M. Bellovin's message of "Thu, 12 Apr 2007 11:05:54 -0400")
Errors-To: owner-nanog@merit.edu
* 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-)
