Re: <draft-ietf-6man-rfc1981bis-05.txt>

[Bob Hinden <[e-mail]>]

Tim,

> On Apr 3, 2017, at 4:20 AM, Tim Chown <[e-mail]> wrote:
> 
> Hi Bob,
> 
> These generally look good, a few comments in-line…

Thanks.  Comments below.

Bob


> 
>> On 31 Mar 2017, at 16:32, Bob Hinden <[e-mail]> wrote:
>> 
>> Hi,
>> 
>> I published a new version of rfc1981bis (-05).  Links to the document below.
>> 
>> The changes in this version are based on comments in IETF last call reviews by Gorry Fairhurst, Joe Touch, Susan Hares, Stewart Bryant, Rifaat Shekh-Yusef, and Donald Eastlake.  Many thank to the reviewers as I think the document is significantly improved, it is much better aligned with current transport practice.
>> 
>> The changes include:
>> 
>>  o  Clarify that the purpose of PMTUD is to reduce the need
>>     for IPv6 Fragmentation.
>> 
>>  o  Added text to Introduction about effects on PMTUD when
>>     ICMPv6 messages are blocked.
> 
> I think "are susceptible to loss if" should read “are susceptible to packet loss if” or perhaps "are susceptible to problematic connectivity if “

I prefer the latter.  I will hold that for the next update.

> 
> I notice that some text in RFC1981bis uses RFC2119-style MUST/SHOULD/etc text, but the document doesn’t include the 2119 “boilerplate”.  Should this be added?  And should the use of should/SHOULD, must/MUST, etc be reviewed through the document?

That style was inherited from RFC1981, which was written before RFC2119.  I am hesitant to add RFC2119 and then have to do a review of all RFC2119 words and not break interoperability.

> 
> There’s a discrepancy between 1981bis and 2460bis on PMTUD implementation.  1981bis says SHOULD implement, 2460bis says implementation is “strongly recommended” - perhaps be consistent?

SHOULD and “strongly recommended” are very close if not equivalent.

> 
>>  o  Clarified in Section 4. that nodes should validate the
>>     payload of ICMPv6 PTB messages per RFC4443.
>> 
>>  o  Removed text in Section 5.2 about the number of paths to a
>>     destination.
>> 
>>  o  Changed title of Section 5.4 to "Packetization layer
>>     actions".
>> 
>>  o  Clarified first paragraph in Section 5.4 to to cover all
>>     packetization layers, not just TCP.
>> 
>>  o  Clarified text in Section 5.4 to use normal retransmission
>>     methods.
>> 
>>  o  Add clarification to Note in Section 5.4 about
>>     retransmissions.
>> 
>>  o  Removed text in Section 5.4 that described 4.2BSD as it is
>>     now obsolete.
>> 
>>  o  Removed reference to TP4 in Section 5.5.
>> 
>>  o  Updated text in Section 5.5 about NFS including adding a
>>     current reference to NFS and removing obsolete text.
>> 
>>  o  Revised text in Section 6 to clarify first attack
>>     response.
>> 
>>  o  Added new text in Section 6 to clarify the effect of
>>     ICMPv6 filtering on PMTUD.
> 
> Perhaps reference RFC4890 here?

Thanks.  I think that makes sense.
> 
>>  o  Aligned terminology for the packetization layer
>>     terminology.
>> 
>>  o  Editorial changes.
>> 
>> A diff from the previous version can be found at:
>> 
>>  https://tools.ietf.org/rfcdiff?url2=draft-ietf-6man-rfc1981bis-05.txt
>> 
>> Please review.
>> 
>> This is part of the project to move the core IPv6 specifications to Internet Standard.
> 
> Best wishes,
> Tim
> 
>> 
>> Thanks,
>> Bob
>> 
>>> A new version of I-D, draft-ietf-6man-rfc1981bis-05.txt
>>> has been successfully submitted by Robert M. Hinden and posted to the
>>> IETF repository.
>>> 
>>> Name:		draft-ietf-6man-rfc1981bis
>>> Revision:	05
>>> Title:		Path MTU Discovery for IP version 6
>>> Document date:	2017-03-31
>>> Group:		6man
>>> Pages:		18
>>> URL:            https://www.ietf.org/internet-drafts/draft-ietf-6man-rfc1981bis-05.txt
>>> Status:         https://datatracker.ietf.org/doc/draft-ietf-6man-rfc1981bis/
>>> Htmlized:       https://tools.ietf.org/html/draft-ietf-6man-rfc1981bis-05
>>> Htmlized:       https://datatracker.ietf.org/doc/html/draft-ietf-6man-rfc1981bis-05
>>> Diff:           https://www.ietf.org/rfcdiff?url2=draft-ietf-6man-rfc1981bis-05
>>> 
>>> Abstract:
>>> This document describes Path MTU Discovery for IP version 6.  It is
>>> largely derived from RFC 1191, which describes Path MTU Discovery for
>>> IP version 4.  It obsoletes RFC1981.
>> 
>> 
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