IPv6 end user addressing

Sat Aug 6 20:14:08 UTC 2011

On Sat, Aug 6, 2011 at 12:36 PM, Owen DeLong <owen at delong.com> wrote:
> On Aug 6, 2011, at 3:15 AM, Jeff Wheeler wrote:
>> Note that in this thread, you advocate three things that are a little
>> tough to make work together:
>> * hierarchical addressing plan / routing
>> * nibble-aligned addressing plan
>> * minimum /48 per customer
>>
> Hasn't been hard so far.

Well, you aren't actually doing this on your network today.  If you
practiced what you are preaching, you would not be carrying aggregate
routes to your tunnel broker gateways across your whole backbone.
Perhaps you also wouldn't use one allocation on the tunnel broker
gateway for /64s and another, a /37 in the case of Ashburn for
example, for users who self-provision a /48 from it.  Also, of course,
your default assignment plan is /64, not /48, even though there are
typically around, what, 10k tunnels active network-wide?

To be clear, you don't do any of the three things you advocate above
where Hurricane Electric's tunnel broker service is concerned.

> I think we were talking about access customers. I don't see giving /48s
> to individual dedicated servers as I don't see them having hierarchy
> behind them. I would think that a /48 per TOR switch would be
> reasonable in that case.

I wish there was more discussion about IPv6 addressing plans in
hosting environments on this list.  I think that, rarely, customers
will decide to tunnel from their home or office to their "dedicated
server," co-lo rack, etc.  My addressing policies provide for this
type of customer to receive a /56 upon request without breaking my
hierarchical addressing scheme.  If they need more than that, the
layer-3 aggregator has to inject an additional route into the POP
area.  If a whole bunch of customers on one aggregator ask for /56,
then the aggregator needs an extra /48 (which might really mean
growing its existing /48 to a shorter route.)

> However, requesting more than a /32 is perfectly reasonable. In
> the ARIN region, policy 2011-3.

My read of that policy, and please correct me if I misunderstand, is
that it recognizes only a two-level hierarchy.  This would mean that
an ISP could use some bits to represent a geographic region, a POP, or
an aggregation router / address pool, but it does not grant them
justification to reserve bits for all these purposes.

> density, even in 20 years. I realize that customer density in
> urban areas does tend to increase, but, assuming a maximum
> 50% market penetration, serving a city the size of Philadelphia
> out of a single POP still seems unlikely to me.

AT&T serves some entire states out of a single POP, as far as layer-3
termination is concerned.

-- 
Jeff S Wheeler <jsw at inconcepts.biz>
Sr Network Operator  /  Innovative Network Concepts