[Re: http://tools.ietf.org/search/draft-hain-ipv6-ulac-01]

Christopher Morrow morrowc.lists at gmail.com
Thu Apr 22 00:51:51 CDT 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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