[ppml] ripe-55/presentations/bush-ipv6-transition.pdf

michael.dillon at bt.com michael.dillon at bt.com
Fri Oct 26 15:12:41 EDT 2007

> regardless, the technology has existed since 1977. it's 
> called m4 (or cpp).

Macro and scripting languages were invented a lot earlier than 1977.
These days Python seems to be the favourite to add a scripting language
to an application.

> if appropriate in your environment, using ULA-{C,L,U} for 
> inside tunnel addressing can also decrease the probability of 
> having to renumber those addresses down to limit(1/x, x->Inf).

The only kind of ULA that exists currently is the kind defined in RFC
4193. There may be no other kinds since RFC 4193 ULA addresses do the
job that is needed, and there is enough space allocated to give everyone
118 different /48s if anyone had such a need. There is a handy tool here
to generate your own ULA and if you feel the need, you can also add it
to the registry but that is not necessary if you don't want to.

> there are plenty of things that make renumbering annoying, 
> but it's not rocket science nor is it impossible. anyone who 
> has had to renumber V4 a few times should have the scars and 
> the vision to take advantage of the improvements/features in 
> IPv6-land that make renumbering easier there.

And most importantly, IPv6 is greenfield so you can plan for, and test,
renumbering from day 1.

--Michael Dillon

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