IPv6 woes - RFC

Thu Sep 23 01:42:50 UTC 2021

> On Sep 22, 2021, at 07:47 , Masataka Ohta <mohta at necom830.hpcl.titech.ac.jp> wrote:
> 
> Owen DeLong wrote:
> 
>>> As mergers of ASes increases the number of announcements and IPv4
>>> addresses were allocated a lot earlier than those of IPv6,
>>> comparing the current numbers of announcements is not meaningful.
>> Mergers of ASes does not increase announcements in IPv4 nearly as
>> much as slow-start and repeated expanding requests for additional
>> IPv4 space have.
> 
> That *was* a factor, when increased number of subscribers
> meant more free addresses.

It’s still a factor as many providers are purchasing addresses rather than deploy CGN
because they don’t want the expensive phone calls CGN causes.

> Today, as /24 can afford hundreds of thousands of subscribers
> by NAT, only very large retail ISPs need more than one
> announcement for IPv4.

I fail to grasp this desire to move the majority of users from second class citizens of the
network to third class all in the interests of forestalling the inevitable.

> 
>>> As a result, size of global routing table will keep increasing
>>> unless there are other factors to limit it.
>> Sure, but it’s very clear that the rate of increase for IPv6 appears
>> to be roughly 1/8th that of IPv4,
> 
> It merely means IPv6 is not deployed at all by small ISPs
> and multihomed sites.

Not true. Judging by the number of /48s in the table, IPv6 is relatively
widely deployed by multi homed end sites and judging by the number
of /32 to /40 prefixes, also widely deployed by small-iso ISPs.

> 
> > The reality is that IPv4 will never be completely disaggregated into
> > /24s
> 
> You are so optimistic.

Yes, I’ll be surprised if (e.g. Apple, HP) part out their /8s in to /24s.

I’ll be surprised if a bunch of large organizations fully part out
their /16s and such.

I doubt any major eyeball ISPs will be significantly disbursing or
disaggregating any of their large blocks any time soon.

I suppose you can call that optimism. I call it realism.

Frankly, the faster IPv4 fully fragments, the better because that only
serves to make continuing to carry it all the more expensive, further
making the case for IPv6.

> 
> > and IPv6 will never be completely disaggregated into /48s, so
> > this is actually meaningless and not predictive in any way.
> 
> That IPv6 will be disaggregated into /40 or even /32 is disastrous.

Which it won’t.

It’s unlikely we will fully deploy 2000::/3 in the lifetime of anyone
on this list today.

>> There is no need for such motivation in IPv6 and better yet,
> 
> Then, in a long run, IPv6 will be disaggregated into /32 or /40.

Not likely… Too many providers and large organizations getting
/20s and /24s for that to happen.

>> since
>> the two organizations have fully globally unique addresses deployed
>> throughout their network, there's no risk of collisions in RFC-1918
>> space necessitating large renumbering projects to merge the networks.
> 
> You fully misunderstand why NAT is so popular today defeating IPv6.

Maybe… I certainly don’t understand why it is popular. It’s simply awful.

> Even if two organizations are merged, sites of the organizations
> are, in general, not merged.

Seems rather pointless and counterproductive.

> As private address space behind NAT is used by each site
> independently, there is no renumbering occur for the private
> addresses.

Well, as GUA would be globally unique to each site, there would be
a full ability to merge the sites _AND_ no renumbering cost.

Can you explain any way in which NAT is somehow better?

Owen