Re: [tcpm] RFC793bis draft 14 Reserved Bits

Wesley Eddy <wes@mti-systems.com> Wed, 04 December 2019 14:59 UTC

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To: Joe Touch <touch@strayalpha.com>, "Rodney W. Grimes" <4bone@gndrsh.dnsmgr.net>
Cc: "tcpm@ietf.org" <tcpm@ietf.org>
References: <201911280244.xAS2iX3T010083@gndrsh.dnsmgr.net> <991312DB-9503-4253-8C87-3CBCA6AB99F1@strayalpha.com>
From: Wesley Eddy <wes@mti-systems.com>
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Date: Wed, 04 Dec 2019 09:59:33 -0500
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Subject: Re: [tcpm] RFC793bis draft 14 Reserved Bits
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On 11/27/2019 10:52 PM, Joe Touch wrote:
>
>> On Nov 27, 2019, at 6:44 PM, Rodney W. Grimes <4bone@gndrsh.dnsmgr.net> wrote:
>>
>>> Hi tcpm,
>>>
>>> Sorry for bumping this, maybe it got overlooked during 106.
>>>
>>> Catching up on draft-ietf-tcpm-rfc793bis-14, I was wondering why the rsrvd bits are not explicitly stated as a formal MUST requirement:
>>>
>>> "Must be zero in generated segments and must be ignored in received segments, if corresponding future features are unimplemented by the sending or receiving host."
>>>
>>> To my understanding, the current phrasing is up to interpretation, i.e., someone might opt to not implement it as stated due to the missing formal MUST - Please prove me wrong if I am missing something.
>> I would even like to see it go further and add "they MUST be ignored by the network, and traverse the network unchanged.”
> Perhaps further explicitly:
>
> they MUST be ignored by the network and MUST traverse the network unchanged


This clarification seems good to me, and it looks like everyone who's 
chimed in so far agrees, so I can put it into the upcoming revision.