[Re: http://tools.ietf.org/search/draft-hain-ipv6-ulac-01]
Christopher Morrow
morrowc.lists at gmail.com
Thu Apr 22 05:51:51 UTC 2010
On Wed, Apr 21, 2010 at 9:35 PM, <Valdis.Kletnieks at vt.edu> wrote:
> On Thu, 22 Apr 2010 07:30:51 +0930, Mark Smith said:
>
>> " The following table shows the probability of a collision for a range
>> of connections using a 40-bit Global ID field.
>>
>> Connections Probability of Collision
>>
>> 2 1.81*10^-12
>> 10 4.54*10^-11
>> 100 4.54*10^-09
>> 1000 4.54*10^-07
>> 10000 4.54*10^-05
>>
>> Based on this analysis, the uniqueness of locally generated Global
>> IDs is adequate for sites planning a small to moderate amount of
>> inter-site communication using locally generated Global IDs."
>
> There is a measured rate by RIRs and the like on the order of 10^-6 for
> accidentally issuing duplicate integers (roughly approximated by 2 cases of
> duplicate ASNs out of (300K routes + 30K ASNs). In other words, unless you
> have over 1,000 or so backdoor links, you're more likely to get screwed over by
> an administrative drone fscking up your paperwork than you are of a statistical
> collision.
it's not about the frequency of collision, it's about the cost to
rectify one/two/some.
and the complexity this adds to every host/router/device in/around the
network (dns, firewalls, acls, etc... icky)
-chris
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