Re: [6lo] Generation of IPv6 IIDs

Erik Nordmark <nordmark@sonic.net> Thu, 24 July 2014 12:21 UTC

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Date: Thu, 24 Jul 2014 05:21:16 -0700
From: Erik Nordmark <nordmark@sonic.net>
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To: "Jonathan Hui (johui)" <johui@cisco.com>, Erik Nordmark <nordmark@acm.org>
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Cc: "6lo-chairs@tools.ietf.org" <6lo-chairs@tools.ietf.org>, "6man Chairs (6man-chairs@tools.ietf.org)" <6man-chairs@tools.ietf.org>, Erik Nordmark <nordmark@cisco.com>, Dave Thaler <dthaler@microsoft.com>, Samita Chakrabarti <samita.chakrabarti@ericsson.com>, "6lo@ietf.org" <6lo@ietf.org>, Fernando Gont <fgont@si6networks.com>, "draft-ietf-6man-default-iids@tools.ietf.org" <draft-ietf-6man-default-iids@tools.ietf.org>
Subject: Re: [6lo] Generation of IPv6 IIDs
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On 7/23/14, 10:25 PM, Jonathan Hui (johui) wrote:
> Note that RFC 6282 already provides the option:
> - If the IID can be derived from MAC address, great.
> - If not, things will still work just with reduced efficiency.
>
> Section 10 of RFC 4944 also provides the same option, but has since been replaced by the encoding specified in RFC 6282.
>
> Also note that 802.15.4 interfaces have both a stable MAC address (EUI-64) and a locally-significant, dynamic MAC address (Short Address).  Many of the arguments against MAC-address-based IIDs may not apply when using Short Addresses.
>

The issue I know about is in RFC 6775 which would fail to deliver errors 
to an ARO if the host doesn't have a link-local address with a 
EUI-64-based IID.

RFC 6775 (6lowpan-nd) makes the assumption that the host always has a 
link-local address configured with the EUI-64 of the host.
That assumption is used in section 6.5.2 to send errors back to hosts.
Note that we already know of a solution, which is local to the router 
implementation, which is already captured in section 9.7 in 
draft-chakrabarti-nordmark-6man-efficient-nd.

    Erik