Re: Is Fragmentation at IP layer even needed ?

Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp> Sun, 14 February 2016 01:26 UTC

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Subject: Re: Is Fragmentation at IP layer even needed ?
To: Joe Touch <touch@isi.edu>, ietf@ietf.org
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From: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
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Date: Sun, 14 Feb 2016 10:26:11 +0900
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Joe Touch wrote:

>> Remember, with IPv6, the firewall can't fragment the reassembled
>> packets.
> 
> Routers shouldn't reassemble, but then routers aren't supposed to look
> beyond L3. You cannot have it both ways.
> 
> Once you inspect L4, you *are* acting as a host.

That is an abstract nonsense by you and others who do not
understand layering at all, which constitutes part of the
collective stupidity.

QoS (not CoS but real QoS) capable routers must inspect L4. Though
fragmentation is generally prohibited for QoS, it is merely because
increased link overhead changes bandwidth requirement, which does
not mean QoS capable routers are acting as a host.

> As Fred pointed out, existing devices already emulate reassembly without
> emmitting the reassembled result.

As I pointed out, if it were acceptable, we could widely accept
fragmentation overhead.

Warren Kumari wrote:

> So, this entire thread (which has reminded me why I stopped
> participating in v6ops) is just a terminology issue? ;-)

People in v6 committee are not acting as professionals.

							Masataka Ohta