First, thanks everyone for the discussion. I learned more from this than a LOT of other discussions on IPv6. I now have a plan and I didn't before...
It looks to me that one really has to know his customer's needs to plan out the allocation of IPv6 space. That leads me to believe that a /56 is going to work for everyone on this network because, at this time, only very, very few of our largest customers might possibly have a need for more than 256 /64 subnets. In fact, almost all household DSL customers here only have one LAN and I could get away with /64s for them because they wouldn't know the difference. But in an effort to simplify the lives of the network folks here I am thinking of a /56 for everyone and a /48 on request.
Now I just gotta wrap my brain around 4.7x10^21 addresses for each customer. Absolutely staggering.
scott
First, thanks everyone for the discussion. I learned more from this than a LOT of other discussions on IPv6. I now have a plan and I didn't before...
It looks to me that one really has to know his customer's needs to plan out the allocation of IPv6 space. That leads me to believe that a /56 is going to work for everyone on this network because, at this time, only very, very few of our largest customers might possibly have a need for more than 256 /64 subnets. In fact, almost all household DSL customers here only have one LAN and I could get away with /64s for them because they wouldn't know the difference. But in an effort to simplify the lives of the network folks here I am thinking of a /56 for everyone and a /48 on request.
Out of curiosity, what in form would a request for a /48 need to be? A
checkbox on the application form, or some sort of written
justification? Remember that with an initial RIR allocation of a /32,
you've got 65K /48s ... so they're pretty cheap to give away.
Now I just gotta wrap my brain around 4.7x10^21 addresses for each customer. Absolutely staggering.
Ever calculated how many Ethernet nodes you can attach to a single LAN
with 2^46 unicast addresses? That's a staggering number too.
Regards,
Mark.
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?
randy
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
Regards,
Mark.
Question. Whats the ethernet 48-bit MAC space usage atm? Does anyone
have a graph showing an E-Day? 
Adrian
Apparently there's a foreseeable one, hence EUI-64s. Novell'll have to
extend their IPX node addressing to 64 bits.
Regards,
Mark.
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.
Regards
Marshall
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.
Here's where I got the version I first read. The full text/pdf is
available if you have or create yourself an ACM login :
http://portal.acm.org/citation.cfm?id=800081.802680
Regards,
Mark.