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Re: Is Fragmentation at IP layer even needed ?

Joe Touch <touch@isi.edu> Mon, 08 February 2016 21:23 UTC

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Subject: Re: Is Fragmentation at IP layer even needed ?
To: Phillip Hallam-Baker <phill@hallambaker.com>, ietf <ietf@ietf.org>
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From: Joe Touch <touch@isi.edu>
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Date: Mon, 08 Feb 2016 13:22:59 -0800
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On 2/8/2016 12:44 PM, Phillip Hallam-Baker wrote:
> Seems to me that we might be misreading the original proposal. There
> are two ways to read it:
> 
> 1) In future all Internet routing gear MUST NOT fragment IP packets.

IPv6 is that future, FWIW.

> 2) Take fragmentation out of the endpoint stack.
> 
> It seems to me that these are very different proposals. I fully
> endorse the first if we add the caveat 'except to support legacy, non
> jumbo frame capable links'.

Where legacy == IPv4, yes. But even then, IPv4 fragmentation except at
the endpoints is already somewhat deprecated based on IP ID values (see
RFC 6864).

Joe

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