Re: [Masque] WGLC for "Requirements for a MASQUE Protocol to Proxy IP Traffic"

[David Schinazi <[e-mail]>]

Thanks Chris B,

I've created a PR that incorporates your MTU text, and also should answer
Magnus' question about trust:
https://github.com/ietf-wg-masque/draft-ietf-masque-ip-proxy-reqs/pull/33/files

Thanks,
David

On Fri, Jun 11, 2021 at 8:07 AM Spencer Dawkins at IETF <
[e-mail]> wrote:

> Chris,
>
> On Fri, Jun 11, 2021 at 9:20 AM Chris Box <[e-mail]>
> wrote:
>
>> The endpoints in this document are the endpoints of the tunnel.
>>> The goal of the MTU requirement is to mention that these endpoints
>>> can share what they view as the max MTU. That would be the MTU
>>> of the tunnel itself. You're right that connections that go through the
>>> tunnel but don't terminate on the tunnel endpoints would need to
>>> also take into account MTUs for the IP hops on either side of the
>>> tunnel. One way to accomplish that is PMTUD between the ends of
>>> that connection.
>>>
>>
>> That makes sense. In that case, can we clarify the wording? Something
>> like this perhaps?
>>
>>    The protocol will allow tunnel endpoints to inform each other of the Maximum
>>    Transmission Unit (MTU) they are willing to forward.  This will allow
>>    avoiding some IP fragmentation, especially as IPv6 does not allow IP
>>    fragmentation by nodes along the path. In cases where the tunnel endpoint
>>
>>    is not the same as the communication endpoint, tunnel endpoints are
>>
>>    expected to apply the guidance on UDP tunnels in [BCP145].
>>
>>
>> Chris
>>
>
> Your question was a good one. I think your proposal is also helpful,
> especially with the pointer to  BCP 145.
>
> Thank you for that.
>
> Best,
>
> Spencer
>