Re: [Int-area] New Version Notification for draft-bonica-intarea-lossless-pmtud-00.txt

Joe,

You have a point that this solution may never be widely deployed. So, I have cranked the intended status back to EXPERIMENTAL and removed the IANA request. (We can work with experimental code points.)

We will do the experiment and report on results.

                                                 Ron

Juniper Business Use Only

-----Original Message-----
From: Joe Touch <touch@strayalpha.com> 
Sent: Wednesday, October 30, 2019 12:44 AM
To: Ron Bonica <rbonica@juniper.net>
Cc: int-area@ietf.org
Subject: Re: [Int-area] New Version Notification for draft-bonica-intarea-lossless-pmtud-00.txt

Hi, Ron,

A few things come to mind. The first one, IMO, renders the rest somewhat less important.

Joe

-------------

- this approach applies only to IPv4; not sure it’s worth trying to optimize for only that case
	(it requires on-path fragmentation permitted)

- this approach relies on ICMPs, so it’s as robust (or, more to the point, not) as PMTUD
	if ICMPs can find the reverse path from the dest, why wouldn’t the routers?
	i.e., isn’t the problem with ICMPs not just routers not sending them but firewalls BLOCKING them?
	(i.e., if ICMPs would work here, PMTU would have worked, rendering this unnecessary)

- why does this doc assume the max ICMP is 576?
	we’re still talking IPv4 here; it’s still 68 (that’s why only 64 bits of the orig payload are guaranteed)
	(yes, your note in the end of sec 1 is relevant, but given v4-in-v4 tunneling, it’s possible that paths might be smaller than the 576 assumption)

- why would this approach find the largest fragment through a system?
	rfc1812 talks about various strategies, one of which is “equal sized”, which might never find the max the way you propose 

> On Oct 29, 2019, at 9:53 AM, Ron Bonica <rbonica=40juniper.net@dmarc.ietf.org> wrote:
> 
> Folks,
> 
> Please review and comment.
> 
>                        Ron
> 
> 
> 
> Juniper Business Use Only
> 
> -----Original Message-----
> From: internet-drafts@ietf.org <internet-drafts@ietf.org> 
> Sent: Tuesday, October 29, 2019 11:48 AM
> To: Ron Bonica <rbonica@juniper.net>; Hakan Alpan <halpan@hnc.edu>; Radon Rosborough <rrosborough@hmc.edu>; Bradely Newton <bnewton@hmc.edu>; Miles President <mpresident@hmc.edu>; Manoj Nayak <manojnayak@juniper.net>
> Subject: New Version Notification for draft-bonica-intarea-lossless-pmtud-00.txt
> 
> 
> A new version of I-D, draft-bonica-intarea-lossless-pmtud-00.txt
> has been successfully submitted by Ron Bonica and posted to the IETF repository.
> 
> Name:		draft-bonica-intarea-lossless-pmtud
> Revision:	00
> Title:		Lossless Path MTU Discovery (PMTUD)
> Document date:	2019-10-29
> Group:		Individual Submission
> Pages:		8
> URL:            https://urldefense.com/v3/__https://tools.ietf.org/html/draft-bonica-intarea-lossless-pmtud-00__;!8WoA6RjC81c!SaG54qXv3mOmFFinOp93hDtn-j4u5ZzUbomMfaHAujluBDj7pJq_RtQMALmTf6K4$ 
> 
> 
> 
> Abstract:
>   This document describes alternative IPv4 PMTUD procedures that do not
>   prevent IP fragmentation and do no rely on the network's ability to
>   deliver ICMP Destination Unreachable messages to the source node.
>   This document also defines a new ICMP message.  IPv4 nodes emit this
>   new message when they reassemble a fragmented packet.
> 
> 
> 
> 
> Please note that it may take a couple of minutes from the time of submission until the htmlized version and diff are available at tools.ietf.org.
> 
> The IETF Secretariat
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