ipv6 addressing - non-routable equivalents?

[Jonathan Guthrie]

On Tue, 3 Oct 2000, David Gethings wrote:

> On Sun, 1 Oct 2000, Jonathan Guthrie wrote:

> > What I don't understand is what to do if you want multiple global
> > addresses on a single computer.  Is there some way of generating multiple
> > IPv6 addresses from a single Ethernet address or am I supposed to generate
> > random global addresses and do a collision detection or do I have to buy a
> > bunch of old, dead Ethernet cards and use their addresses?  With the large
> > address space available in IPv6, it makes sense to use address-based
> > virtual hosting and server addresses should be global, or so I understand.
 
> If I recall the IPv6 RFC correctly you can ues part of the last 64 bits
> for multiple addresses on a single computer.

> As you know the last 64 bits of an IPv6 address are taken from the
> computers MAC address (if you wish to allocate in that manner). But a MAC
> address is only 48 bits long, leaving a tasty 8 bits.
 
> As I understand it the computer *can* use these 8 bits to allocate
> multiple addresses without too much further configuration. How you do this
> in pratice though, I have no idea as I haven't looked into it.

I presume the "8 bits" is part of a brain fog as 64-48 is 16, not 8.

My reading of rfc2373 (which can be retrieved from
ftp://ftp.isi.edu/in-notes/rfc2373.txt, if you have a mind to read it) is
that those 16 bits (which are inserted starting at bit 24) are required to
be 0xfffe.

I don't want to speak ill of the standards process as it's tough enough to
accomplish as it is, but didn't anybody consider the fact that people are
going to want to use address-based virtual hosting when designing this
scheme, or am I missing something?
-- 
Jonathan Guthrie (jguthrie@brokersys.com)
Brokersys  +281-580-3358   http://www.brokersys.com/
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