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Re: 64bit MAC addresses and SLAAC

Fernando Gont <fgont@si6networks.com> Wed, 17 June 2020 19:08 UTC

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Subject: Re: 64bit MAC addresses and SLAAC
To: Philip Homburg <pch-ipv6-ietf-6@u-1.phicoh.com>, ipv6@ietf.org
References: <e8a25961-5ac9-d35e-77dd-bf86f45cd077@gmail.com> <a17ae9f3-001c-07f6-84f9-a0ca583e6a00@gmail.com> <7AE5B6D0-AB01-4077-A9EF-5BD86F428681@gmail.com> <CAC8QAcdDjQvonke7hytV8pCYsTAjATNi560v_b32jus_jDW8bw@mail.gmail.com> <b43a00f5-c957-923a-cef4-ed541ebdb39a@gmail.com> <a96f1262-d152-dc09-1c2f-b2604ca21890@si6networks.com> <m1jlb8u-0000JDC@stereo.hq.phicoh.net>
From: Fernando Gont <fgont@si6networks.com>
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Date: Wed, 17 Jun 2020 16:06:28 -0300
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On 17/6/20 13:42, Philip Homburg wrote:
>> 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.

Well, it does allow correlation of network activities across addresses. 
In a way, that's kind of the same as when a host moves across networks.



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

+1


-- 
Fernando Gont
SI6 Networks
e-mail: fgont@si6networks.com
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492

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