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On 3 Mar 2009 Chuck Anderson wrote:</span></font>
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> On Tue, Mar 03, 2009 at 02:19:33AM -0600, David Farmer wrote:</span></font>
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> > The following is my IPv6 link local address, fe80::208:74ff:fe24:ac0a, my </span></font>
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> > mac address is 0008:7424:ac0a, this is the simple transformation defined in </span></font>
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> > RFC 2464. Therefore a DHCP server can be assured to get the EUI-64 </span></font>
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> > version of the MAC address. Transforming that back to a 48-bit MAC and </span></font>
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> > allowing operations in the DHCP server based on the MAC address should </span></font>
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> > be possible without modification of DHCPv6 clients or DHCPv6 relay agents.</span></font>
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> </span></font>
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> > 64 address rather than leaving it up to the client through SLAAC to use its </span></font>
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> > EUI-64 or a privacy address. </span></font>
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> </span></font>
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> What about clients using privacy addressing (RFC 3041)? It isn't </span></font>
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> clear to me from reading the RFC if this affects link local addresses, </span></font>
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> but if it does, they won't have a MAC address embedded in their link </span></font>
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> local address.</span></font>
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I haven't seen any implementations of RFC 3041 that use
privacy extensions on the link local address, but I haven't
exhaustively looked either. I'll note that RFC 3041 is an
extension to SLAAC, which technically occurs after the link
local address is assigned and uses the link local address to
communicate with the local routers. Also, in my quick reread
of RFC 3041, it seems to be limited to "global-scoped
addresses"</span></font>
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But, I agree, I don't technically see any reason that you
couldn't use RFC 3041 like privacy for a link local address, and
that would break this assumption. But, I think it is a valid
assumption, at least for now. If that changes in the future, I
think I'm ok with that. I see this as a short-term crutch. Longer
term, we all need retool and redo our processes and
procedures to move to DUIDs. I do like some of the ideas
behind DUIDs. But, asking everyone to do that now, just
creates a barrier to adoption of IPv6. And as I said in another
post, we have enough of those already.</span></font>
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A further note on using RFC3041 on link local address; If you
used RFC 3041 for a link local address, and changed it over
time like is envisioned in RFC 3041, that would probably have
many unintended consequences.</span></font>
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=======================================================</span></font>
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David Farmer Email: farmer@umn.edu</span></font>
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Office of Information Technology</span></font>
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Networking & Telecomunication Services</span></font>
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University of Minnesota Phone: 612-626-
0815</span></font>
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2218 University Ave SE Cell: 612-812-9952</span></font>
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Minneapolis, MN 55414-3029 FAX: 612-626-
1818</span></font>
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=======================================================</span></font>
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