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Re: 64bit MAC addresses and SLAAC

Fernando Gont <fgont@si6networks.com> Wed, 17 June 2020 15:14 UTC

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Subject: Re: 64bit MAC addresses and SLAAC
To: Alexandre Petrescu <alexandre.petrescu@gmail.com>, IPv6 <ipv6@ietf.org>
References: <e8a25961-5ac9-d35e-77dd-bf86f45cd077@gmail.com> <a17ae9f3-001c-07f6-84f9-a0ca583e6a00@gmail.com>
From: Fernando Gont <fgont@si6networks.com>
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Date: Wed, 17 Jun 2020 12:00:50 -0300
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On 15/6/20 17:23, Alexandre Petrescu wrote:
> Hi,
> 
> Before the sanitary situation I was studying an issue at ISO.
> 
> The issue is about 64bit MAC addresses and SLAAC.
> 
> SLAAC needs a 48bit MAC addresses in order to work,

Nope. SLAAC nees you to come up with a 64-bit IID. It used to be the 
case that link-layer-specific RFCs would tell you how to come up with 
such a 64-bit IID -- typically based on the underlying MAC address. -- 
but we have moved away with that (see RFC8064 and RFC7217)


> and it can not work 
> with a 64bit MAC address; (but yes, it can with 64bit IIDs).

Quite the contrary, the SLAAC IID length was changed from 48-bits to 
64-bits to accommodate link-layers that employ 64-bit link-layer addresses.

Thanks,
-- 
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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