Re: Why ULA: low collision chance (Was: IPv6 fc00::/7 — Unique local addresses)

Fri Oct 22 00:09:16 UTC 2010

On Thu, Oct 21, 2010 at 6:27 PM, Joel Jaeggli <joelja at bogus.com> wrote:
> On 10/21/10 6:02 AM, William Herrin wrote:
>> On Thu, Oct 21, 2010 at 8:14 AM, Ray Soucy <rps at maine.edu> wrote:
>>> That's assuming ULA would be the primary addressing scheme used.  If
>>> that became the norm, I agree, the extra uniqueness would be
>>> desirable, perhaps to the point that you should be asking an authority
>>> for FC00::/8 space to be assigned.  But then why wouldn't you just ask
>>> for a GUA at that point.
>>
>> Because you might want space that doesn't route on the Internet so
>> that if your routes accidentally leak external folks still can't reach
>> you?
>
> Announce your gua and then blackhole it and monitor your prefix. you can
> tell if you're leaking. it's generally pretty hard to tell if you're
> leaking rfc 1918 since your advertisement may well work depending on the
> filters of your peers but not very far.

Joel,

I have a condensate overflow pan under my computer room air
conditioner that collects water if it leaks. I also have an alarm that
alerts me if there's a leak and careful maintenance to prevent it from
leaking in the first place. But I still have the pan. Even though a
leak could fill the pan and overflow, I insist on having a pan there
to try to catch the water.

How many guesses do you need to figure out why?

Regards,
Bill Herrin

-- 
William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004