RE: [**EXTERNAL**] Re: the race to the bottom problem

["STARK, BARBARA H" <[e-mail]>]

> Would it help if the problem statemen clarifies that:
> 
> - There is no race to the bottom. We are not trying to solve ISP problem by
> allowing longer than 64bit prefixes,
> - It is not about restricting the ISP prefix assignments to minimum one 64bit
> prefix, by imposing 64bit SLAAC prefix limitation on the clients,
> - Minimum of one 64bit prefix limitation should be imposed by other
> network elements, rather than clients. Edge routers can block >64bit
> prefixes,
> - Clients should be enabled to use >64bit prefixes for SLAAC to address X, Y, Z
> problems, and
> - Operators engineering >64bit subnets need to evaluate how low is the IID;
> should maximum prefix length be 70 or 96 or ... (for security or other
> reasons)?
> 
> Dusan

I'm thinking it might be reasonable to impose a requirement on CE routers (and devices in similar roles) that it MUST NOT accept delegation of a prefix longer than 64 bits on any interface using a technology that only exists on WAN links (e.g., DSL, PON, DOCSIS). This doesn't fully solve the problem. But if it's hard to get routers that will accept such delegations on WAN-only links, it will discourage most operators from doing them. From a business analysis case, the cost of providing prefixes with length <= 64 would be less than the cost of making sure all their customers have CE routers in place that do not have this limitation.
Barbara

> 
> On 2020-11-06, 9:15 AM, "Alexandre Petrescu"
> <[e-mail]> wrote:
> 
> 
> 
> Le 06/11/2020 à 11:36, Fernando Gont a écrit :
> > On 6/11/20 07:04, Alexandre Petrescu wrote:
> >> I have been reminded in private about 'race to the bottom'.
> >>
> >> In the Variable SLAAC solution draft we do touch on the problem:
> >>
> >>> The "race to the bottom problem" - is the problem where allowing
> >>>  prefixes longer than 64 to be used in SLAAC will lead to 65, 66
> >>> and so on, up to 127 and 128 allocations.  At that point the
> >>> bottom would be reached and thus impossible to extend the network
> >>> further.
> >>
> >> A solution is then proposed in section 8 titled "Greater than 64
> >> bit prefix usage by ISPs is strictly prohibited".
> >
> > Then we'd need an RFC for formally creating the Internet
> > police/militia. (possibly a very bad timing for an already bad
> > idea).
> 
> So we need to attenuate that 'strictly prohibited' wording and improve a
> way forward.
> 
> Alex
> 
> >
> > Thanks,
> 
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