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Re: Is Fragmentation at IP layer even needed ?

Joe Touch <touch@isi.edu> Mon, 08 February 2016 21:20 UTC

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Subject: Re: Is Fragmentation at IP layer even needed ?
To: Alexey Eromenko <al4321@gmail.com>, John Levine <johnl@taugh.com>
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From: Joe Touch <touch@isi.edu>
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Date: Mon, 08 Feb 2016 13:19:36 -0800
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On 2/8/2016 8:08 AM, Alexey Eromenko wrote:
> Basically, Fragmentation, as specified in RFC-2460 (IPv6), solves the
> problem ONLY for packet-sized between 1280 and 1500 bytes. Which is why
> I doubt if it is useful at all.

It's exactly what lets encapsulation tunneling occur and reoccur at will.

I.e., once you split a 1500 byte packet into 1280 and 220 and
encapsulate each of the results, you get to do it again.

Without fragmentation, arbitrary recursive direct (IP-in-IP) tunneling
is impossible.

Joe

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