[v6ops] Re: [IPv6]Re: Is the P flag even necessary? M flag already does enough (Re: Re: A detail review of draft-ietf-6man-pio-pflag-04)

[Michael Breuer <[e-mail]>]

Hey Ted,

Thanks for bringing this up.

I’m currently struggling with a CE router that receives a /48 from the ISP and, whatever an inner router requests via IA_PD, this device always delegates /57.

Coming from this example to the more general. In my experience, CE router makers do a lot of weird things and, for the better of the Internet, they really need precise and good guidance.

So, whatever the WG thinks is the right prefix length, the document should give explicit guidance on the prefix length.

> On 5. Aug 2024, at 20:30, Ted Lemon <[e-mail]> wrote:
> 
> On Mon, Aug 5, 2024 at 11:16 AM Timothy Winters <[e-mail]> wrote:
> v6ops has a draft for PD on the LAN to improve this situation.
> 
> https://datatracker.ietf.org/doc/draft-ietf-v6ops-cpe-lan-pd/
> 
> Please feel free to send comments, we are about to do WGLC on it.
> 
> Hey, Tim. I hadn't read the document in a while. I see this text in the last requirement:
> 
> The IPv6 CE Router SHOULD by default provision IA_PD IA prefixes with a prefix-length of 64.
> 
> I read this as "if the DHCP client doesn't specify a narrower prefix, the CE router SHOULD .. 64"
> 
> Is that what you intended? If not, I think you need to say more. If that is what you intended, this won't work, because if we stack CE routers, I expect every CE router to ask for a /48, rather than not specifying, and that would mean that we'd always delegate the narrowest remaining subset of the outer CE router's delegation to the first inner router that makes a request.