Subject: Confirm consensus to adopt draft-hinden-6man-mtu-option

From: Ole Troan <[email-masked]>
Date: Thu, 25 Jul 2019 10:17:17 -0400

At the 6MAN session at the Montreal IETF there was a positive hum to adopt the experimental <draft-hinden-6man-mtu-option>
as a 6MAN working group document:

Title : IPv6 Minimum Path MTU Hop-by-Hop Option
Author : R. Hinden, G. Fairhurst
Filename : draft-hinden-6man-mtu-option-02
Pages : 14
Date : 2019-07-05
 
https://datatracker.ietf.org/doc/draft-hinden-6man-mtu-option/ 

This is a call to confirm this consensus.
If you _object to adopting this document, please respond to the mailing list.
Editoril suggestions can be sent to the authors.

This confirmation call will end on 8 August 2019.

Best Regards,
Ole, 6man co-chair

---

From: David Lamparter <[email-masked]>
Date: Thu, 25 Jul 2019 16:22:52 +0200

On Thu, Jul 25, 2019 at 10:17:17AM -0400, Ole Troan wrote:
> At the 6MAN session at the Montreal IETF there was a positive hum to
> adopt the experimental <draft-hinden-6man-mtu-option> as a 6MAN
> working group document:

I agree that this document should proceed in the working group.

(Even if the reality turns out to be that it's not feasible to do, it's
appropriate to work on this in WG context.)

-David

---

From: Erik Kline <[email-masked]>
Date: Thu, 25 Jul 2019 14:33:00 -0400

> appropriate to work on this in WG context.)
hum++

---

From: "Templin (US), Fred L" <[email-masked]>
Date: Thu, 25 Jul 2019 19:57:15 +0000

> -----Original Message-----
> From: ipv6 [mailto:[email-masked]] On Behalf Of Ole Troan
> Sent: Thursday, July 25, 2019 7:17 AM
> To: 6man WG <[email-masked]>
> Cc: 6man Chairs <[email-masked]>
> Subject: Confirm consensus to adopt draft-hinden-6man-mtu-option
> 

Was not present at the hum, but please proceed with adoption.

> --------------------------------------------------------------------
> IETF IPv6 working group mailing list
> [email-masked]
> Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6
> --------------------------------------------------------------------

---

From: Tom Herbert <[email-masked]>
Date: Thu, 25 Jul 2019 17:59:53 -0400

I agree with adoption.

On Thu, Jul 25, 2019, 3:57 PM Templin (US), Fred L <
[email-masked]> wrote:

> adopt the experimental <draft-hinden-6man-mtu-option>

---

From: Gyan Mishra <[email-masked]>
Date: Sat, 27 Jul 2019 02:30:18 -0400

Please proceed with adoption.

This draft will really help with issues with using pmtud to adjust MSS on
host endpoints not working due to icmp packet to big being dropped
resulting in flow being dropped or not negotiating the highest minimum mtu.

Internally within Verizon with jumbo frames for IPv6 we use adjust mss to
adjust mtu down where jumbo is not supported.

Gyan S. Mishra

IT Network Engineering & Technology

Verizon Communications Inc. (VZ)

13101 Columbia Pike FDC1 3rd Floor

Silver Spring, MD 20904

United States

Phone: 301 502-1347

Email: [email-masked]

www.linkedin.com/in/GYAN-MISHRA-RS-SP-MPLS-IPV6-EXPERT

-- 

Gyan S. Mishra

IT Network Engineering & Technology

Verizon Communications Inc. (VZ)

13101 Columbia Pike FDC1 3rd Floor

Silver Spring, MD 20904

United States

Phone: 301 502-1347

Email: [email-masked]

www.linkedin.com/in/GYAN-MISHRA-RS-SP-MPLS-IPV6-EXPERT

---

From: Nick Hilliard <[email-masked]>
Date: Wed, 31 Jul 2019 23:34:06 +0100

> Editoril suggestions can be sent to the authors.

the usefulness of this approach to pmtu detection is based on the 
assertion in section 6.1:

>    o  The design of this Hop-by-Hop Option makes it feasible to be
>       implemented within the fast path of a router, because the required
>       processing is simple.

The problem is the word "feasible", which is not a word that means 
anything in this context.  For an IETF contributor, it means that the 
practical implications of this EH can be put to one side while the rest 
of the draft can be discussed; for a silicon designer or asic 
programmer, it means the specification can be ignored due to the cost / 
performance constraints they operate within.

Despite intense pressure on vendors to parse EHs in the fast path since 
ipv6 was defined 20 years ago, there is an awful lot of hardware out 
there which doesn't, and there aren't compelling reasons to think this 
will change any time in the future due to the performance impact of 
handling the complexity of EHs at high speed.

Unfortunately, this pushes this draft into the category of aspirational 
rather than providing a workable approach to handling ipv6 pmtu 
detection.  I wish this weren't the case.

As a related observation, rfc7872 suggests that HBH headers are 
associated with high rates of packet drops.

Sorry to take such a pessimistic view of the draft but I don't think 
it's workable and consequently don't think it's worth pushing towards 
rfc status, even experimental.

Nick

---

From: Loganaden Velvindron <[email-masked]>
Date: Thu, 1 Aug 2019 08:23:59 +0400

I support adoption of this document.

On Thursday, July 25, 2019, Ole Troan <[email-masked]> wrote:

> At the 6MAN session at the Montreal IETF there was a positive hum to adopt
> the experimental <draft-hinden-6man-mtu-option>

---

From: Luuk Hendriks <[email-masked]>
Date: Thu, 1 Aug 2019 08:43:36 +0200

Please adopt this document.

 luuk