Re: Short 6MAN WG Last Call: <draft-ietf-6man-node-req-bis-09.txt>

[Mark Smith <[e-mail]>]

Hi Bert,


On Thu, 12 May 2011 17:22:05 -0500
"Manfredi, Albert E" <[e-mail]> wrote:

> Mark Smith wrote:
> 
> > I think it would be reasonable to make DHCP a SHOULD, however
> > I've thought that one of the reasons SLAAC exists is to provide
> > simpler and lighter weight address configuration method for resource
> > constrained end-nodes such as embedded ones. So perhaps it could be
> > worth mentioning that an example of an exception to the SHOULD would be
> > those types of end-nodes.
> 
> More generally, I'd say SLAAC exists because with IPv6 it's possible to assign globally unique IP addresses to hosts, without risk of collisions, without having to have the network specify all of the 128 bits.
> 
> But in situations where the address provided to a host must be completely predictable, SLAAC won't work.
> 
> I don't think that resource-constrained need to be a significant criterion?
> 

I'd thought that SLAAC was created instead of just making an IPv6
equivalent of DHCPv4 and leaving that as a single address
configuration mechanism was because it required less maintained state
and processing. Less maintained state and processing would best suit low
CPU powered and memory devices, which is why I suggested "loosening"
the SHOULD for DHCPv6 a bit for those devices. SLAAC is of course
convenient in other situations too.

Regards,
Mark.