Re: [EXTERNAL] Re: 64bit MAC addresses and SLAAC

[Fernando Gont <[e-mail]>]

On 17/6/20 13:17, Templin (US), Fred L wrote:
> Fernando, I think an unspoken assumption in these past several messages is that
> privacy is ALWAYS a required property.

The assumption is that you fail on the safe side -- that's the essence 
of RFC8064.


> However, there are cases where address
> privacy is not only not required, but it is also desirable and useful to be able to
> track a node by a stable and unchanging IP address or prefix.
> 
> This is not intended to challenge the non-use of MAC addresses in Interface
> Identifiers per your documents, but just to say that in some environments the
> randomization and constant changing of IP addresses may actual run counter to
> operational objectives.

FWIW, RFC7217 produces "stable per network" as that's what is typically 
a somewhat "sane" operational requirement. Normally, at the time you 
require constant (across networks) IIDs, you have:

1) ++evilness, xor,
2) if you don't operate the target networks, you cannot enforce that 
(think networks requiring managed address configuration via DHCPv6), xor,
3) You do not need to rely on this, and you could have the hosts report 
the addresses themselves (e.g., dyn dns updates), xor,
4) If you do operate the target networks, you probably can track the 
nodes themselves (e.g., via non-random mac addresses), unless the hosts 
intentionally don't want that (e.g., they randomize their mac addresses)

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [e-mail]
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