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Re: 64bit MAC addresses and SLAAC

Philip Homburg <pch-ipv6-ietf-6@u-1.phicoh.com> Wed, 17 June 2020 16:42 UTC

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To: ipv6@ietf.org
Cc: Fernando Gont <fgont@si6networks.com>
Subject: Re: 64bit MAC addresses and SLAAC
From: Philip Homburg <pch-ipv6-ietf-6@u-1.phicoh.com>
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Date: Wed, 17 Jun 2020 18:42:27 +0200
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> The case of "same IID with distinct prefixes" is the same as using
> the same IID as the host moves from one network to another. And
> that's quite bad for privacy. PLease see RFC7721.

I think they are quite different. If a host moves between different networks
and keeps the same IID, then the movements of the host can be tracked.

If a host is connected to a subnet that has multiple prefixes, then using
the same IID for all prefixes only has marginally less privacy than
using different IIDs.

That said, in my opinion people who want any kind of control over what
addresses are used, should use DHCPv6 (Or manual/static configuration)

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