nanog mailing list archives

Re: v6 subnet size for DSL & leased line customers


From: Mark Smith <nanog () 85d5b20a518b8f6864949bd940457dc124746ddc nosense org>
Date: Sun, 30 Dec 2007 10:46:09 +1030


On Sat, 29 Dec 2007 15:14:25 -0500
Marshall Eubanks <tme () multicasttech com> wrote:


On Dec 27, 2007, at 11:19 PM, Mark Smith wrote:


On Fri, 28 Dec 2007 12:57:45 +0900
Randy Bush <randy () psg com> wrote:

Ever calculated how many Ethernet nodes you can attach to a  
single LAN
with 2^46 unicast addresses?

you mean operationally successfully, or just for marketing glossies?


Theoretically. What I find a bit hard to understand is peoples'
seemingly complete acceptance of the 'gross' amount of ethernet  
address
space there is available with 46 bits available for unicast addressing
on a single LAN segment, yet confusion and struggle over the  
allocation
of additional IPv6 bits addressing bits for the same purpose - the
operational convenience of having addressing "work out of the box" or
be simpler to understand and easier to work with.

Once I realised that IPv6's fixed sized node addressing model was
similar to Ethernet's, I then started wondering why Ethernet was like
it was - and then found a paper that explains it :

"48-bit Absolute Internet and Ethernet Host Numbers"
http://ethernethistory.typepad.com/papers/HostNumbers.pdf


Would it be possible to find the even part of this paper ? This  
version only has the odd numbered pages.


Hmm, you're right. The version I originally read was from somewhere
else, and that was complete. I figured this one was more "original" as
it's on one of the papers author's websites, so I've remembered that
one, and even deleted my original electronic copy for this one. I'll try to find
the other copy.

Regards,
Mark.

-- 

        "Sheep are slow and tasty, and therefore must remain constantly
         alert."
                                   - Bruce Schneier, "Beyond Fear"


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