[153454] in North American Network Operators' Group
Re: IPv6 /64 links (was Re: ipv6 book recommendations?)
daemon@ATHENA.MIT.EDU (Owen DeLong)
Wed Jun 6 16:26:16 2012
From: Owen DeLong <owen@delong.com>
In-Reply-To: <1339012964956-013-00428989.sclark.netwolves.com@sclark66.netwolves.com>
Date: Wed, 6 Jun 2012 13:21:09 -0700
To: Steve Clark <sclark@netwolves.com>
Cc: 'NANOG list' <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Jun 6, 2012, at 1:02 PM, Steve Clark wrote:
> On 06/06/2012 03:05 PM, Owen DeLong wrote:
>>=20
>> It is because of IEEE EUI-64 standard.
>>=20
>> It was believed at the time of IPv6 development that EUI-48 would run =
out of
>> numbers and IEEE had proposed going to EUI-64. While IEEE still =
hasn't
>> quite made that change (though Firewire does appear to use EUI-64 =
already),
>> it will likely occur prior to the EOL for IPv6.
>>=20
>> There is a simple algorithm used by IEEE for mapping EUI-48 onto the =
EUI-64
>> space.
>>=20
>> The 0x02 bit of the first octet of an EUI-64 address is an L-Flag, =
indicating that
>> the address was locally generated (if it is a 1) vs. IEEE/vendor =
assigned (if it is a 0).
>>=20
>> The mapping process takes the EUI-48 address XX:YY:ZZ:RR:SS:TT and =
maps
>> it as follows:
>>=20
>> let AA =3D XX xor 0x02.
>>=20
>> AAYY:ZZff:feRR:SSTT
>>=20
>> ff:fe above is literal.
>>=20
>> IPv6 was originally going to be a 32-bit address space, but, the =
developers
> did you mean "originally going to be a 64-bit address space"...
Uh, yeah... Sorry... Brain fart. Originally a 64-bit address space.
Owen
