[IPv6]Re: Adoption call for draft-bonica-6man-deprecate-router-alert

[Ron Bonica <[e-mail]>]

Ole,

Inline..... [RB]

                    RB



Juniper Business Use Only

________________________________
From: Ole Troan <[e-mail]>
Sent: Tuesday, June 11, 2024 4:15 AM
To: 6man WG <[e-mail]>
Cc: 6man Chairs <[e-mail]>; [e-mail] <[e-mail]>; Jen Linkova <[e-mail]>
Subject: Re: [IPv6]Adoption call for draft-bonica-6man-deprecate-router-alert

[External Email. Be cautious of content]


The skeptic in me found at least four objections.

- optics. Router Alert is used as part of MLD by every IPv6 implementation on the planet. I’m skeptical about the message the IETF gives by deprecating one of the fundamental building blocks of IPv6. Even if this draft doesn’t have any consequence for implementation. It just looks awkward.

[RB] Are the optics of dropping packets containing HBH any better? The optics are already bad.

- problem. How many new uses of Router Alert has appeared over the years? Is this a “problem” worth solving?

[RB] The HBH processing document talks about future protocols that might use the Router Alert. So, it is conceivable that someone might develop a protocol that relies on the Router Alert in the future. If we want that protocol developer to consider alternatives to the router alert, we should provide guidance now. It would be anti-social to do so after the fact.


- implementation. Isn’t the cat already out of the bag? Every IPv6 implementation must handle router alert and must have control plane policing / throttling in place. This draft isn’t changing that.

[RB] The draft addresses this point. It is only about future uses.

- new work. What if there is a new protocol requiring a punt out of the forwarding path by an intermediate router? Isn’t HBH + Router Alert the easiest and most performant way for the forwarding plane to do that? Alternatively we’ll end up with magic cookies like STUN (0x2112A442). Where the forwarding plane would have to parse the EH chain before looking at a cookie.

[RB] Could you tell me more about such protocols. Specifically, why could they not use the same strategy that RSVP used when it moved away from the Router Alert Option.


Cheers,
Ole


> On 11 Jun 2024, at 01:23, Jen Linkova <[e-mail]> wrote:
>
> This email starts 6MAN adoption call for the following document:
>
> Title : Deprecation Of The IPv6 Router Alert Option
> Authors : Ron Bonica
> Date : 2024-02-19
>
> https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-bonica-6man-deprecate-router-alert/__;!!NEt6yMaO-gk!AYILtdvfufBGj1g55yeLs0H2PT77BZuj6YCJhzagKT8_BBqeAW_Csb_H7HsQ8dyJNd3YrZlsV0ciPVY5Wg$
>
> Substantive comments, statements of support for adopting this
> document or objections to the adoption should be sent to the mailing
> list.  Editorial suggestions can be sent to the authors.
> .
> This adoption call will end on June 26th 2024.
>
> Regards,
> Jen Linkova on behalf of 6MAN chairs.
>
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