DHCP, Dynamic DNS, and IPv6

[Ted Lemon]

On Aug 30, 2008, at 8:19 AM, Simon Hobson wrote:
> Is it possible for the V4 server to determine what the V6 ID would be
> from the information in the request packets ?

No.   The V6 id is constructed so as to be permanent, and consequently  
there's some salt that's added when it's generated that the DHCPv6  
server has no way to predict.

However, given a V6 DUID, the DHCP server should generally be able to  
guess what the V4 client identifier would be for any client that uses  
the client's MAC address as an identifier.   Of course, now that I  
think of it, this falls over if the client has two network interfaces,  
since generally speaking the client will only use the MAC address of  
one of those interfaces to generate the client identifier.   Sigh.