Addressing plan exercise for our IPv6 course

Sun Jul 25 08:40:19 UTC 2010

On (2010-07-25 17:32 +1000), Karl Auer wrote:

> The risk of a ULA prefix conflict is for *all practical purposes* zero.

http://www.wolframalpha.com/input/?i=1-((2^40)!)%2F((2^40)^1000000+((2^40)-1000000)!)+

It wouldn't puke nice graph with 'n', it did try, but never finished.

So if there are million assigned ULA's there is 36.5% chance of collision, if
formula is right.

If operator fscks-up their residential DSL product, lets say the assign all the
/128 user could want, but from single shared /64 subnet, not routing dedicated
/48 to each customer. Users who need to route, will want solution and some
vendor will step in, providing router which will auto-assign ULA + NAT66, will
that vendor sell million copies of said CPE?

But I don't think it is interesting to discuss the random chance of collisions,
as human factor will guarantee collisions, many people will assign fd::/48 to
get short and memorable addresses in their network. (You've made your bed, now
lie in it.)

If your IT staff includes personnel who've done painful renumbering due to M&A,
there is good chance they'll allocate random, otherwise they'll likely opt for
short and memorable network, as they did with RFC1918.
Just because we get IPv6, doesn't mean people will get sudden burst of insight
in design and engineering.

-- 
  ++ytti