Re: Updating to RFC6434 to deal with 8200-style header insertion by IPIP

Fernando Gont <fernando@gont.com.ar> Mon, 06 November 2017 18:02 UTC

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Subject: Re: Updating to RFC6434 to deal with 8200-style header insertion by IPIP
To: Brian E Carpenter <brian.e.carpenter@gmail.com>, "C. M. Heard" <heard@pobox.com>, 6man WG <ipv6@ietf.org>
Cc: Michael Richardson <mcr+ietf@sandelman.ca>
References: <CACL_3VETxNVQ+YD5j6ZiWjycQ=ojAuWwB23offNdVKm+S9c_7A@mail.gmail.com> <23308.1509623865@obiwan.sandelman.ca> <CACL_3VFrcombGczXU6Zz=Pk1u2GE=wGG-r+yEefdHai1REqXmQ@mail.gmail.com> <c8911f45-2afc-9d26-c0a8-1017d034a251@gmail.com>
From: Fernando Gont <fernando@gont.com.ar>
Message-ID: <1e62fab6-c434-a474-e53b-e4c7f2d83de0@gont.com.ar>
Date: Mon, 6 Nov 2017 15:02:14 -0300
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On 11/02/2017 04:33 PM, Brian E Carpenter wrote:
> On 03/11/2017 04:26, C. M. Heard wrote:
>> On Thu, Nov 2, 2017, Michael Richardson <mcr+ietf@sandelman.ca> wrote:
>>
>>>
>>> C. M. Heard <heard@pobox.com> wrote:
>>>     > On Wed, 01 Nov 2017, Michael Richardson wrote:
>>>     >> Yet we skip other extension headers in order to find the ULP.
>>>
>>>     > Not so. An end node that encounters an unrecognized extension header
>>> is
>>>
>>> Both AH and IPIP are well known and recognized extension headers.
> 
> AH is an extension header. "IPIP" isn't. It's Protocol 41, and Protocol 41
> is otherwise known as IPv6. (That's why it's also called IPPROTO_IPV6).
> In RFC8200 terms that makes it an "upper-layer header". Strictly speaking,
> RFC8200 doesn't specify what to do with an unrecognized upper-layer header.

Based on the std, anything that is unknown is an EH. In the context of
RFC8200/FC2460, there's only:

* Known EHs
* Known ULP
* Unknown EHs


with the last one being the default branch :-)


-- 
Fernando Gont
e-mail: fernando@gont.com.ar || fgont@si6networks.com
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