[arin-ppml] IPv4 Depletion as an ARIN policy concern

[michael.dillon at bt.com]

> Reusing the same ULA prefix would defeat the purpose (Uniqueness).  
> Better to have the ISPs do random prefix generations for 
> their clients.

How often does difficulty in merging the network of consumer A
and the network of consumer B, have a chance of scuttling the
merger, or have a material impact on the financial terms of
the merger?

As far as I can see it, in divorce and remarriage situations,
the network topology is not even relevant. Therefore ULA
uniqueness serves no purpose to consumers. And probably very
little purpose for small businesses as well.

Now look on the ISP side? Uniqueness means one more thing
to track and one more thing to go wrong when configuring
a new customer or repairing a customer fault. In this case,
having one ULA prefix to be used for all customers' 
private internal addressing is a good thing. It's best
that they don't use the same ULA prefix as the ISP down
the road, but no big catastrophe if they do.

It's a different thing when it comes to the internal private
addressing of the ISP's own network, where they definitely
should generate their own random prefix according to RFC 4193,
or if that is too confusing, just go to
<http://www.sixxs.net/tools/grh/ula/>
plug in a MAC address from one of the routers, and click Generate.
Register it as well for good measure.

Note that my comments about reusing a ULA, only applies to the
internal customer infrastructure (prefixes longer than /48) in
those customers where the ISP sets things up, and the customer
leaves it alone. Savvy tech customer will, of course, generate
their own unique ULA in preparation for that day, 10 years down
the road, when they are bought out by Huawei-Cisco or CTC-Verizon.

--Michael Dillon