Re: [v6ops] ULA precedence [Thoughts about wider operational input]

[Nick Buraglio <[e-mail]>]

I am happy to participate, and would like to help with this effort.

nb



On Thu, Mar 24, 2022 at 3:04 PM Brian E Carpenter
<[e-mail]> wrote:
>
> (Trying, far too late, to change the Subject to be the actual subject...)
>
> I wasn't paying enough attention when RFC6724 was done. I think it's even
> more wrong each time I look at it. For example, it has the consequence that
> if a pair of hosts have both RFC1918 and ULA addresses, the default for
> communication between them is RFC1918. D'Oh. If two hosts have ULAs in the
> same /64, they will nevertheless try IPv4 first. D'Oh. And the default table
> in RFC6724 is sticky in practice, even if configurable in theory.
>
> I think this needs serious work (in 6MAN most likely).
>
> Regards
>     Brian Carpenter
>
> On 25-Mar-22 00:29, Philip Homburg wrote:
> >> (Dual-stack cannot be the answer anyway - it will have all the issues
> >> of IPv4, plus the added complications of dual-stack.  Services need to
> >> be dual-stack, but for all the rest, single-stack IPv6 needs to be
> >> the end goal - see facebook etc)
> >
> > Obviously, on an IPv6-only system, there is no IPv4, so the relative
> > priority of ULA compared to IPv4 does not matter.
> >
> > I'm curious what IPv4aaS we want to deploy. I consider NAT64 a complete
> > disaster (even if the form of 464xlat). Given how the internet works,
> > we will probably end up with NAT64 everywhere until the end of times.
> >
> >> This is not what I had in mind.  If "we" decide that ULA is a good
> >> way forward, IETF can update RFCs, and vendors will eventually
> >> update their base OS.  It might take 5 years, but so will everything
> >> else in Big Enterprise land.
> >
> > The problem with ULA is that we have lots of installations where hosts with
> > a ULA address don't have access to the IPv6 internet. Often, CPEs announce
> > a ULA when the CPE doesn't have an IPv6 uplink.
> >
> > In contrast, where RFC 1918 was meant for local IPv4 communication, it is
> > now on a very large scale the primary method for a host to reach the IPv4
> > internet.
> >
> > So to avoid the situation where we say that ULA is local and then use it
> > to connect to the IPv6 internet, we should just allocate a new space. And
> > explicitly give it the property to connect to the IPv6 internet through
> > through some sort of address translation.
> >
> > There is also a nice tie-in with PI. Obviously, putting millions of PI
> > prefixes in BGP does not scale.
> >
> > On the other hand, there is no such limit if the PI space is used behind NAT.
> >
> >
> >
> > _______________________________________________
> > v6ops mailing list
> > [e-mail]
> > https://www.ietf.org/mailman/listinfo/v6ops
> > .
> >
>
> _______________________________________________
> v6ops mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/v6ops