Sorry, please disregard. I need coffee.

Lars

On 2015-6-26, at 13:17, Lucy yong <[email protected]> wrote:
> 
> Lars,
> 
> I am confused by your comment. This thread is about GRE encapsulation over 
> IPv6 network. Not about UDP encapsulation.
> 
> Lucy
> 
> -----Original Message-----
> From: Eggert, Lars [mailto:[email protected]]
> Sent: Friday, June 26, 2015 3:14 PM
> To: Lucy yong
> Cc: Ronald Bonica; [email protected]
> Subject: Re: [Int-area] I-D Action:draft-ietf-intarea-gre-ipv6-09.txt
> 
> Hi,
> 
> the UDP checksum field is not a codepoint to exchange configuration 
> information in.
> 
> In other words, zero has been a special case since the first specification of 
> UDP. But all other values cannot be overloaded to have special meaning.
> 
> Lars
> 
> On 2015-6-25, at 15:59, Lucy yong <[email protected]> wrote:
>> 
>> Ron,
>> 
>> Quick fix. :)
>> 
>>  The GRE ingress node SHOULD set the Checksum Present field to zero.
>>  However, implementations MAY support a configuration option that
>>  causes the GRE ingress node to set the Checksum Present field to one.
>> 
>> Does this mean that, by default, GRE ingress node sets Checksum Present 
>> field to zero, and it is optional for an implementation to support GRE 
>> Checksum? Please clarify. Should it be "implementations MUST support a 
>> configuration option ...".
>> 
>> IMHO: The text in Section 2.1 and 4.2 has some redundancy. Please check.
>> 
>> Thanks,
>> Lucy
>> 
>> -----Original Message-----
>> From: Ronald Bonica [mailto:[email protected]]
>> Sent: Thursday, June 25, 2015 4:21 PM
>> To: [email protected]; Lucy yong
>> Subject: RE: [Int-area] FW: I-D
>> Action:draft-ietf-intarea-gre-ipv6-09.txt
>> 
>> Lucy,
>> 
>> Good point. I have posted a new version of the draft that omits the 
>> offending paragraph.
>> 
>> I tried to wordsmith the offending paragraph so that it would say what I 
>> meant. However, when I did that, it became redundant with the preceding 
>> paragraph.
>> 
>> The final sentence in Section 2.1 encourages operators to evaluate the risks 
>> in their network and configure the GRE ingress appropriately. So, if they 
>> need the Checksum Present field to be set to one, they can configure that 
>> behavior.
>> 
>> 
>> Ron
>> 
>> 
>> 
>>> 
>>> Message: 3
>>> Date: Thu, 25 Jun 2015 17:15:38 +0000
>>> From: Lucy yong <[email protected]>
>>> To: "[email protected]" <[email protected]>
>>> Subject: [Int-area] FW:  I-D Action:
>>>     draft-ietf-intarea-gre-ipv6-09.txt
>>> Message-ID: <2691CE0099834E4A9C5044EEC662BB9D5718B286@dfweml701-
>>> chm>
>>> Content-Type: text/plain; charset="us-ascii"
>>> 
>>> Some comments:
>>> 
>>> Section 2.1 description is not right. GRE checksum can't detect a
>>> mis- delivered packet and neither the checksum function in the
>>> payload. GRE checksum only provides integrity check on GRE header and GRE 
>>> payload.
>>> 
>>> Only IPv4 payload has the equivalent payload integrity check as of
>>> GRE checksum. GRE does not directly carry TCP or UDP. When GRE
>>> payload protocol is not IPv6, the payload still can carry TCP or UDP.
>>> For example, GRE payload is either Ethernet or MPLS that carries
>>> IP/TCP/UDP flows. This satisfies "the payload carries TCP or UDP"; in
>>> this case, TCP and UDP checksum does not provide the same integrity check 
>>> as of GRE checksum.
>>> 
>>> GRE can be used in many ways. These examples seem not sufficient for
>>> the justification of GRE checksum zero.
>>> 
>>> Since Ipv6 has flow label, it would be good for the draft to describe
>>> use of flow label in IPv6 header.
>>> 
>>> Regards,
>>> Lucy
>>> 
>>> 
>>> 
>>> 
>>> -----Original Message-----
>>> From: Int-area [mailto:[email protected]] On Behalf Of
>>> internet- [email protected]
>>> Sent: Thursday, June 25, 2015 11:07 AM
>>> To: [email protected]
>>> Cc: [email protected]
>>> Subject: [Int-area] I-D Action: draft-ietf-intarea-gre-ipv6-09.txt
>>> 
>>> 
>>> A New Internet-Draft is available from the on-line Internet-Drafts 
>>> directories.
>>> This draft is a work item of the Internet Area Working Group Working
>>> Group of the IETF.
>>> 
>>>       Title           : IPv6 Support for Generic Routing Encapsulation (GRE)
>>>       Authors         : Carlos Pignataro
>>>                         Ron Bonica
>>>                         Suresh Krishnan
>>>     Filename        : draft-ietf-intarea-gre-ipv6-09.txt
>>>     Pages           : 10
>>>     Date            : 2015-06-25
>>> 
>>> Abstract:
>>>  Generic Routing Encapsulation (GRE) can be used to carry any network-
>>>  layer payload protocol over any network-layer delivery protocol.  GRE
>>>  procedures are specified for IPv4, used as either the payload or
>>>  delivery protocol.  However, GRE procedures are not specified for
>>>  IPv6.
>>> 
>>>  This document specifies GRE procedures for IPv6, used as either the
>>>  payload or delivery protocol.  It updates the GRE specification, RFC
>>>  2784.
>>> 
>>> 
>>> 
>>> The IETF datatracker status page for this draft is:
>>> https://datatracker.ietf.org/doc/draft-ietf-intarea-gre-ipv6/
>>> 
>>> There's also a htmlized version available at:
>>> https://tools.ietf.org/html/draft-ietf-intarea-gre-ipv6-09
>>> 
>>> A diff from the previous version is available at:
>>> https://www.ietf.org/rfcdiff?url2=draft-ietf-intarea-gre-ipv6-09
>>> 
>>> 
>>> 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.
>>> 
>>> Internet-Drafts are also available by anonymous FTP at:
>>> ftp://ftp.ietf.org/internet-drafts/
>>> 
>>> _______________________________________________
>>> Int-area mailing list
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>>> https://www.ietf.org/mailman/listinfo/int-area
>>> 
>>> 
>>> 
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>>> 
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>>> 
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>>> 
>>> End of Int-area Digest, Vol 119, Issue 4
>>> ****************************************
>> 
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