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Re: Updated IID length text

Lorenzo Colitti <lorenzo@google.com> Thu, 19 January 2017 04:26 UTC

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References: <148406593094.22166.2894840062954191477.idtracker@ietfa.amsl.com> <82245ef2-cd34-9bd6-c04e-f262e285f983@gmail.com> <m2d1frhjfn.wl-randy@psg.com> <18e6e13c-e605-48ff-4906-2d5531624d64@gmail.com> <CAKD1Yr1cvZ8Y3+bHeML=Xwqr+YgDspZGnZi=jqQj4qe2kMc4zw@mail.gmail.com> <m2lguffnco.wl-randy@psg.com> <CAKD1Yr1TrTiPRdyutobmb_77XJ7guNzLrg=H_p7qi4BfQ8V=GA@mail.gmail.com> <m2d1frfm6m.wl-randy@psg.com> <CAKD1Yr2Njjd8_Mr+6TRFF6C5pdcX4yFgpFVyEkykDuytu2B8mg@mail.gmail.com> <2A5073777007277764473D78@PSB> <4596c3d4-a337-f08e-7909-f14270b7085f@gmail.com> <CAN-Dau06R3iYRpYLADhvHox4C9qdsJCuxFsJapRhOQcWT4qk_g@mail.gmail.com> <CAO42Z2weZcoHiBzN94QAQ9WGhWR16PmMMFNg=5YLmr_dhPjjpA@mail.gmail.com> <fcc7f136-b5da-527e-b495-5a2d7f7a3ce8@gmail.com> <55bb8bdbfbf4439da0aa702e5bc03e2c@XCH15-06-11.nw.nos.boeing.com> <CAKD1Yr2vmDkUTvSw7-GtKNeMDm1xtAppj+EW9X=-TeKZ6qkXrg@mail.gmail.com> <6b718d09-4a91-8128-0559-d072e1e1d832@si6networks.com> <CAKD1Yr39+gU7U=2i=bHPdj3OK9yOUSFdx3Fk42NZQo32oDbygQ@mail.gmail.com> <a77b4884-809f-4944-5580-6afc11e0f756@si6networks.com>
From: Lorenzo Colitti <lorenzo@google.com>
Date: Thu, 19 Jan 2017 13:25:39 +0900
Message-ID: <CAKD1Yr1cSPBacrk2tZAOOGwR4nSU2NYSrV5ArZLBrOoXTcBNTw@mail.gmail.com>
Subject: Re: Updated IID length text
To: Fernando Gont <fgont@si6networks.com>
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On Thu, Jan 19, 2017 at 1:20 PM, Fernando Gont <fgont@si6networks.com>
wrote:

> > It does make sense. /48 does impact things substantially. However, on
> > like like wifi, the MAC address is the endpoint identifier, so if
> > there's a duplicate MAC you can't get on the network.
>
> Could you please explain how you do the math such that in these two
> scenarios:
>
> #1: SLAAC with 48-bit IIDs, where the IID is a random string of bits
>     (e.g. as resulting from RFC7217)
>
> #2: Traditional SLAAC with 64-bit IIDs, where the IID is generated from
>     a randomized MAC address (and in which, based on how MOdified EUI64
>     IIDs are generated, you have to embed the fixed 16-bit word 0xfffe
>     in the IID)
>

You forgot the "where layer 2 ensures that there are no duplicate MAC
addresses on the network" part of this scenario.

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