using ULA for 'hidden' v6 devices?

Tim Chown tjc at
Thu Jan 26 14:05:05 UTC 2012

Thanks for the comments Ray, a couple of comments in-line.

On 26 Jan 2012, at 12:43, Ray Soucy wrote:

> Local traffic shouldn't need to touch the CPE regardless of ULA or
> GUA.  Also note that we already have the link local scope for traffic
> between hosts on the same link (which is all hosts in a typical home
> network); ULA only becomes useful if routing is involved which is not
> the typical deployment for the home.

The assumption in homenet is that it will become so.

> ULA is useful, on the other hand, if NPT is used.  NPT is not NAT, and
> doesn't have any of the nastiness of NAT.

Well, you still have address rewriting, but prefix-based.

> I think a lot of the question has to do with what the role of CPE will
> be going forward.  As long as we're talking dual-stack, having
> operational consistency between IPv4 and IPv6 makes sense.  If it's an
> IPv6-only environment, then things become a lot more flexible (do we
> even need CPE to include a firewall, or do we say host-based firewalls
> are sufficient, for example).

The initial assumption in homenet is a stateful firewall with hosts inside the homenet using PCP or something similar.


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