[Gen-art] Re: [Last-Call] draft-ietf-v6ops-framework-md-ipv6only-underlay-23 ietf last call Genart review

[Brian E Carpenter <[e-mail]>]

Stewart,

>  For example IPv6 has the assumption (for integrity reasons) that
>  UDP will have a checksum. IPv4 is acrostic on that and frequently sets CS = 0
>  and yet the draft seems to be silent on the consequences.

The draft states clearly that translation complies with RFC7915, which covers
the UDP zero checksum issue explicitly.

You are of correct that other issues _might_ appear during deployment, but this
is only asking for Informational status, although there could be an argument
for going directly to BCP.

(Note to authors: an Implementation Status section would have made it
easier to reply to Stewart!)

Regards/Ngā mihi
    Brian Carpenter

On 25-Jun-26 03:34, Stewart Bryant via Datatracker wrote:
> Document: draft-ietf-v6ops-framework-md-ipv6only-underlay
> Title: Framework for Multi-domain IPv6-only Underlay Network and
> IPv4-as-a-Service Reviewer: Stewart Bryant Review result: Ready with Issues
> 
> I am the assigned Gen-ART reviewer for this draft. The General Area
> Review Team (Gen-ART) reviews all IETF documents being processed
> by the IESG for the IETF Chair.  Please treat these comments just
> like any other last call comments.
> 
> For more information, please see the FAQ at
> 
> <https://wiki.ietf.org/en/group/gen/GenArtFAQ>.
> 
> Document: draft-ietf-v6ops-framework-md-ipv6only-underlay-23
> Reviewer: Stewart Bryant
> Review Date: 2026-06-24
> IETF LC End Date: 2026-06-22
> IESG Telechat date: Not scheduled for a telechat
> 
> Summary: I am reviewing from a GENART perspective and with this perspective I
> think the text of the draft should reassure me that this unconditionally works
> for any legitimate IPv4 protocol stack and any legitimate operation of that
> protocol stack.
> 
> The draft adequately describes how an IPv4 packet is sent and delivered over an
> IPv6 network at the network layer but IPv4/6 hosts have assumptions about the
> network they are using at other layers of the protocol stack and there is no
> in-depth exploration of the wider considerations. Hopefully these are addressed
> in other similar mechanisms that I did not have time to explore, but I think
> the general reader should be reassured in the body of the text.
> 
> Major issues:The draft has covered ICMP by asserting the presence of a
> stateless translator, but I cannot but worry that the are a lot of other
> assumptions built into an IPv4 protocol stack that may surface during
> deployment. For example IPv6 has the assumption (for integrity reasons) that
> UDP will have a checksum. IPv4 is acrostic on that and frequently sets CS = 0
> and yet the draft seems to be silent on the consequences. I wonder if the draft
> needs to be experimental until there is operational experience with the method.
> 
> Minor issues: None
> 
> Nits/editorial comments:There seems to be a minor confusion between Network
> Operator and Network Provider in the text that needs examining. "service
> continuity after IPv4 address exhaustion, network operators (NPs). I assume
> this is just a typo.
> 
>