Re: [v6ops] PMTUD issue discussion

Joe Touch <touch@isi.edu> Fri, 05 September 2014 14:00 UTC

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Date: Fri, 05 Sep 2014 06:59:46 -0700
From: Joe Touch <touch@isi.edu>
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To: "Fred Baker (fred)" <fred@cisco.com>, Fernando Gont <fgont@si6networks.com>
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Cc: "v6ops@ietf.org" <v6ops@ietf.org>, Tom Perrine <tperrine@scea.com>, Fernando Gont <fernando@gont.com.ar>
Subject: Re: [v6ops] PMTUD issue discussion
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On 9/4/2014 5:58 PM, Fred Baker (fred) wrote:
>
> On Sep 5, 2014, at 10:47 AM, Fernando Gont <fgont@si6networks.com> wrote:
>
>> On 09/04/2014 09:24 PM, Fred Baker (fred) wrote:
>>>
>>> On Sep 5, 2014, at 9:33 AM, Fernando Gont <fernando@gont.com.ar>
>>> wrote:
>>>
>>>> What happens when/if such lins employ v6 (whether they really
>>>> offer a "virtual" MTU >=1280).. I just don't know.
>>>
>>> 802.15.4?
>>
>> No. I seem to recall that it was more of a packet radio sort of thing
>> (something predating 802.15.4). I could ask some folks if interested
>> in more details…
>
> I think you missed my point. We have a case in point today, which is
> IPv6 in an IPv6 tunnel encapsulation running on a packet network whose
> MTU is 127 bytes. We call it “6lowpan”, and it runs on IEEE 802.15.4.

That's not IPv6. I don't know what it is, but RFC2460 is clear on the 
minimum MTU for IPv6.

Anyone who pays money for such a thing should return it.

Joe