IPv6 /64 links (was Re: ipv6 book recommendations?)

Wed Jun 6 20:21:09 UTC 2012

On Jun 6, 2012, at 1:02 PM, Steve Clark wrote:

> On 06/06/2012 03:05 PM, Owen DeLong wrote:
>> 
>> It is because of IEEE EUI-64 standard.
>> 
>> 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.
>> 
>> There is a simple algorithm used by IEEE for mapping EUI-48 onto the EUI-64
>> space.
>> 
>> 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).
>> 
>> The mapping process takes the EUI-48 address XX:YY:ZZ:RR:SS:TT and maps
>> it as follows:
>> 
>> let AA = XX xor 0x02.
>> 
>> AAYY:ZZff:feRR:SSTT
>> 
>> ff:fe above is literal.
>> 
>> 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