[ppml] draft-ietf-ipv6-ula-central-02.txt use cases

Per Heldal heldal at eml.cc
Thu Jun 28 04:46:26 EDT 2007

On Thu, 2007-06-28 at 10:12 +0200, Brian E Carpenter wrote:
> On 2007-06-27 13:54, Per Heldal wrote:
> > On Tue, 2007-06-26 at 23:48 -0500, Stephen Sprunk wrote:
> >> If we want to issue address space to folks for "private" use, it needs to be 
> >> out of the same block(s) that the RIRs use to allocate space for "public" 
> >> use, because sooner or later those "private" networks are going to end up 
> >> being publicly routed.
> > 
> > But if we do this shouldn't we also take steps to prevent abuse
> > (hijacking etc) of those "private" blocks. 
> No, I don't think so. ULAs are for local use. We provide a mechanism
> to ensure that they are extremely likely to be unique, but as long as
> they are used locally, and confined locally both by routing and by
> DNS, it actually doesn't matter operationally if someone else uses the
> same prefix in their local area.

I wasn't talking about ULA at all, but about an attempt to limit abuse
of PI or even PA space whenever such blocks are allocated but not
announced externally. Whether allocated PI is used for private purposes
by accident or intentionally doesn't matter in that respect. ULA is no
problem as it's trivial to block all of it with one single

The rest of my rant was about my wish to formalise and automate the
relation between allocation policies and operational practises. I.e. why
keep pretending registry-policies have nothing to do with routing when
so many IDRs in the DFZ has a config full of stuff derived from those


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