[ppml] [address-policy-wg] Those pesky ULAs again

Iljitsch van Beijnum iljitsch at muada.com
Fri Jun 1 18:39:20 EDT 2007

On 1-jun-2007, at 19:00, Paul Vixie wrote:

> yes.  but also because of the other part of my text, which you didn't
> include in your reply so i don't know whether you agreed with it or  
> not:

>>> ... we would have to define "routable", we could face implied  
>>> liability for
>>> routability on "normal address space" (even if we continue to  
>>> disclaim it
>>> in the NRPM as we do now), and we would then walk the slippery  
>>> slope of the
>>> changing definition "largest" with respect to breidbart's maxim:

> 	>> But what *IS* the internet?
> 	> It's the largest equivalence class in the reflexive transitive
> 	> symmetric closure of the relationship "can be reached by an IP
> 	> packet from".		--Seth Breidbart

> in other words, the definition of "routable" depends on who you  
> want to be
> able to exchange packets with.

I'm not sure if I agree that there is a potential liability, but  
then, I'm not a lawyer, I don't play one on TV and the legal system  
where I live is quite different from that where ARIN is.

The question of what "routability" is is not one that I'm interested  
in. We know what this means today, massaging the definition to fit a  
particular purpose can only lead to suboptimal results.

> "local" and "routable", not so much so.

Ok, if that makes you happy:

Routable address space: any block of global unicast address space  
that when announced through or by an internet service provider,  
allows the holder to receive packets addressed to the addresses in  
question from all possible sources connected to the internet without  
additional effort.

ULA fails this test because it falls outside the global unicast block  
and because announcing it to one ISP isn't enough to receive packets  
from all over the world because people will filter.

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