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

Fernando Gont <fernando@gont.com.ar> Mon, 06 November 2017 16:33 UTC

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Subject: Re: Updating to RFC6434 to deal with 8200-style header insertion by IPIP
To: Michael Richardson <mcr+ietf@sandelman.ca>, 6man WG <ipv6@ietf.org>
References: <CAOSSMjUVCSBjbYu3bc7DU+edz2+0+RvU_AMi4FNn2n2075kk9g@mail.gmail.com> <6286.1509408085@obiwan.sandelman.ca> <f9447eb6-fca1-e54c-ff0b-abafa5986960@gmail.com> <25055.1509413008@obiwan.sandelman.ca> <B5488438-0F4B-4362-9B34-6B6FB74D5A49@employees.org> <19111.1509476559@obiwan.sandelman.ca>
From: Fernando Gont <fernando@gont.com.ar>
Message-ID: <37b32942-7d1a-dfd8-288d-ce1f937fc484@gont.com.ar>
Date: Mon, 6 Nov 2017 13:15:43 -0300
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On 10/31/2017 04:02 PM, Michael Richardson wrote:
> 
> Ole Troan <otroan@employees.org> wrote:
>     > Without having thought very much about it... I do think requiring a
>     > host to accept tunnelled packets to itself by default or not, requires
>     > further considerations.
> 
> I agree: it requires further consideration.
> 
>     > I am aware of no implementation that would support this. I would also
>     > be worried about this opening the door for "alternate" paths into the
>     > host stack.
> 
> I agree. Nobody does it this way.
> Yet 8200 (and 2460 before it) says that this is the way to insert headers.

No. EHs are not inserted or removed. When you do IPinIP, you are
creating a brad-new packet, *not* inserting EHs in the existing packet.

Thanks,
-- 
Fernando Gont
e-mail: fernando@gont.com.ar || fgont@si6networks.com
PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1