who gets a /32 [Re: IPV6 renumbering painless?]

Paul Vixie vixie at vix.com
Fri Nov 19 19:49:56 UTC 2004


stephen at sprunk.org ("Stephen Sprunk") writes:

> > isc is multihomed, so it's difficult to imagine what isp we could have
> > taken address space from then, or now.
> 
> According to multi6, you will get PA space from each of your ISPs and
> overlay a prefix from each on every subnet.  I'll save y'all another rant
> on the workability of that model...

please don't.  don't save me from that rant.  let's all hear it.  really.

> Some fear that you would more likely just generate a ULA, use that
> internally, and NAT at the borders.  Or maybe you'd stick with IPv4
> RFC1918 space internally and NAT to IPv6 PA space at your borders.

the internet endpoint type trend is toward SOHO and dsl/cable, and the
provider trend is toward gigantic multinational.  companies who build
their own networks tend to find that the cheapest interoffice backhaul
is IP-in-IP VPN's.  thus is the old model of a 1000-person company buying
a T1 transit connection moving toward the margins.  as i continue to
research my own premises, i find that the style of internetworking 
practiced at isc, which precludes PA space due to multihoming and due
to possible renumbering penalties, is becoming quite rare as a percentage
of the total number of network owners and the total number of endpoints
thus interconnected.  it's sad but it's true and it gives cause to ponder
the future of enabling technologies like internet exchange points.

this may yet lead to a mechanism for qualifying multihomed network builders
to get PI space, since they'll be rare enough to have a low impact on the
global routing table.  on the other hand, transit-provider lock-in is not
officially recognized as having any bearing on any RIR policy in any
region; if that continues to be the case, the rare kind of network i'm most
familiar with will continue to use ipv4 or will only use ipv6 via something
like ULA's.  what this may mean is that approving ULA's will make the
situation better, since network owners will otherwise just pirate unused
space at random.  with ULA's we'll at least have a chance to trace leaks
and try to make BCP38 happen in more places.
-- 
Paul Vixie



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