Faster 'Net growth rate raises fears about routers

Tue Apr 3 17:51:03 UTC 2001

On Tue, 3 Apr 2001 hardie at equinix.com wrote:

> The people who prevent the current global routing table from being
> flooded by /25-/30 announcements are also the people who punch holes
> in their address space for /24s.  Abha's numbers at the ptomaine BOF
> clearly show the effect of RIR policies (spikes around /20 and /19),
> but the bigger effect from my perspective was the spike around /24,
> created (I presume) by the punches in CIDR blocks that providers make
> to allow multi-homing.  I haven't seen good numbers for the
> distribution of punches in a long time, but my limited experience
> indicates that those punches are being made fairly randomly within the
> provider's allocated address space.  This means that the bit
> boundaries don't align and you increasingly have mini-swamps inside
> providers' /19s and /20s.
> 
> Why are providers doing this?  Someone is paying them to do it.  

I don't argue that multihoming is bad. I argue that we're doing it in the
wrong place with negitive consequences.

> Why are customers spending money on this?  My belief is that they
> want more say in their own fate.  That may express itself as
> a desire for redundancy in the case of catastrophic business failures,
> better ability to express their own routing policies, or a simple
> worry that they won't get the best price if they have only one supplier.
> At the core of this, though, is a desire for more control over something
> that they see as increasingly important to their own fate.  

I agree. However, you can offer even greater control and all the other
benefits of multihoming without doing it at the IP layer.

Multihoming at the IP later thus breaking aggregation is like dumping
toxic waste, it cost is largely carried by those not in recept of it's
benefits or any form of payment.

If we can avoid it while still providing the necessary level of service,
then we should seriously investigate such opportunities.

> I think there are various short term work-arounds to the current
> explosion of paths in the routing tables, and I encourage folks to
> join the ptomaine mailing list (ptomaine-request at shrubbery.net) if
> they want to contribute to the solution.

Short term is nice, but it doesn't matter in the long run. :)

> But don't try to accomplish
> it by reducing the ability of the customer to control their own fate.
> There are real economic pressures out there which will prevent that
> class of solution from success.

I never suggested that, I suggested investigating alternatives which
increase customer choice, performance, reliability, and Internet
scalability and potential measures to make the minor inital cost of
implimentation more acceptable.

The obvious intrest here is that most network operators would not have
their customers multihoming at the IP level and thus preventing 
aggregation and polluting the global routing table is there was another
way to achieve the same benefits.