[ppml] IPv6 & /48 [was 2005-1:Business Need for PI Assignments]

william(at)elan.net william at elan.net
Mon Apr 25 18:00:37 EDT 2005

On Mon, 25 Apr 2005, Randy Bush wrote:

> so, if i rephrase that there is no real CURRENT technical reason,

Of course IETF did not want to create new CIDR. But that does not mean 
that such limit would not come based on operational policies and everyone 
wanted to make sure those policies would be the same across the board and
leave and leave enough room for everyone. As an example we do have a limit 
of /24 and smaller blocks are not allowed by most (every!) ISPs to come 
into global routing table.

And as far as /64 boundary it is in fact more then just policy /48 (which 
is similar to /24 operational bgp prefix limit) and a lot of equipment
companies are already setting it up for their devices. Not in theory 
impossile to change but would not be easy either.

> i gather you aree.  interesting side note that the binding to a mac
> address created all sorts of privacy issues as well, see later
> back-patches to v6 such as 3041.

Binding to currently used MAC addresses was never assumed to be way for
future, it was always understood that multiple end-note addressing schemes
would exist. Privacy reasons has just caused creation of such new scheme. 
What I do not like is that now people seem ok with setting up those /64 
bits to just 00 or 01 - this is bad and both increases chance of collision 
and bad for security.

William Leibzon
Elan Networks
william at elan.net

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