host-identifier with IPv6

[Chuck Anderson]

On Wed, Mar 04, 2009 at 11:00:35AM -0700, Ted Lemon wrote:
> On Mar 4, 2009, at 4:30 AM, Frank Sweetser wrote:
>> ... except for DHCPv4, which we still have to track the MAC address  
>> for anyway.
>
> You still need an exception policy for DHCPv4, because the Mac address  
> can change on a DHCPv4 box too.

One problem that using DUIDs for DHCPv6 and MAC for DHCPv4 introduces 
is a "half-broken" system.  Reinstalling the OS gives you a new DUID 
but the MAC stays the same.  If you require the full DUID to be 
registered as a known host for DHCPv6 and the MAC for DHCPv4, now IPv4 
continues to work but IPv6 breaks.  I'd prefer it if IPv4 and IPv6 
either both worked or they both broke at the same time, because 
otherwise you'll be in a situation that is difficult for the end user 
and/or Helpdesk to diagnose.