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Re: Why has RFC 4941 been designed in such a way, that it might cause address conflicts?

Philip Homburg <pch-6man@u-1.phicoh.com> Tue, 15 March 2011 15:56 UTC

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To: Markus Hanauska <hanauska@equinux.de>
Subject: Re: Why has RFC 4941 been designed in such a way, that it might cause address conflicts?
From: Philip Homburg <pch-6man@u-1.phicoh.com>
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In-reply-to: Your message of "Mon, 14 Mar 2011 13:00:11 +0100 ." <C744C51B-F2B0-4137-B39F-54B8D62F1C97@equinux.de>
Date: Tue, 15 Mar 2011 16:58:04 +0100
Cc: ipv6@ietf.org
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In your letter dated Mon, 14 Mar 2011 13:00:11 +0100 you wrote:
>And bear in mind, that other RFCs even mention cases where a device might 
>create its 64 bit host ID entirely "random"; which is even worse than using a 
>hash function.

I think the answer is that is statistically very unlikely that on a single
subnet, a 64-bit random number will ever be equal to any address manually
configured in DHCP.

Is is far more likely that by accident to ethernet cards have the same MAC
address than that a true 64-bit random number will collide with another number
out of a relatively small set.

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