[ppml] [address-policy-wg] Those pesky ULAs again

Kevin Loch kloch at kl.net
Tue May 29 11:04:32 EDT 2007


Leo Bicknell wrote:

> - IPv6 space is not infinite.  It's a 64-72 bit address space.  That's
>   right, subnets with > 256 hosts are very uncommon today, so we've wasted
>   64 bits to number 256 things.  That makes the space effectively on the
>   long end 72 bits.

Excellent point.  I never understood why they didn't just use say 16
bits for the host portion, randomly assign an address and check for 
collisions before use.

>   I predict with the current allocation procedures IPv6 will be
>   "used up" in my lifetime.  I also predict the groups today getting
>   /32's (and larger) will look like the legacy class A holders in
>   20 years time.  When your doorknob automatically requests a ULA-C
>   /64 when you bring it home, and your house has 2,000 of them as every
>   individual system talks to each other we'll be looking at this quite
>   differently.

Why can't your doorknob select a ULA-L /64 and check for collisions
before use?

- Kevin



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