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Re: Is Fragmentation at IP layer even needed ?

Joe Touch <touch@isi.edu> Tue, 09 February 2016 20:27 UTC

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Subject: Re: Is Fragmentation at IP layer even needed ?
To: Ronald Bonica <rbonica@juniper.net>, Alexey Eromenko <al4321@gmail.com>, ietf <ietf@ietf.org>
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From: Joe Touch <touch@isi.edu>
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Date: Tue, 09 Feb 2016 12:26:31 -0800
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On 2/8/2016 9:21 AM, Ronald Bonica wrote:
> Many end-stations work around this problem by sending packets no longer
> that the IPv6 minimum MTU (1280 bytes). This ensures that IPv6
> fragmentation services will never be required.

IPv6 1280 may itself not be fragmented, but it may end up in multiple IP
fragments within an IP tunnel if the tunnel cannot assume an MTU that is
larger.

So if you have tunnels, fragmentation services are always ultimately
required.

Joe

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