Re: [v6ops] draft-ietf-v6ops-pmtud-ecmp-problem WGLC

Brian E Carpenter <> Sun, 31 May 2015 23:45 UTC

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Date: Mon, 01 Jun 2015 11:45:33 +1200
From: Brian E Carpenter <>
Organization: University of Auckland
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Subject: Re: [v6ops] draft-ietf-v6ops-pmtud-ecmp-problem WGLC
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Generally I think this is useful and almost ready.

> 3.1.  Alternatives
>    As an alternative, it may be appropriate to lower the TCP MSS to 1220
>    in order to accommodate 1280 byte MTU.  We consider this undesirable
>    as hosts may not be able to independently set TCP MSS by address-
>    family thereby impacting IPv4, or alternatively that it relies on a
>    middle-box to clamp the MSS independently from the end-systems.

The "that" in the second sentence doesn't parse. I don't understand
what the draft is trying to say about MSS clamping.

Also, shouldn't we say "undesirable but possibly necessary in some
cases"? A server at the mercy of an ISP might *need* to apply MSS clamping.


It's confusing to have these two sections with identical titles:

> 3.1.  Alternatives
> 3.2.1.  Alternatives

Maybe 3.1 should be "MSS-based Alternatives"
and 3.2.1 "Distributed Proxy Alternatives"

On 01/06/2015 06:00, wrote:
> This is to initiate a two week working group last call of
> Please read it now. If you find nits (spelling errors, minor suggested
> wording changes, etc), comment to the authors; if you find greater
> issues, such as disagreeing with a statement or finding additional
> issues that need to be addressed, please post your comments to the
> list.
> We are looking specifically for comments on the importance of the
> document as well as its content. If you have read the document and
> believe it to be of operational utility, that is also an important
> comment to make.
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