Re: REVIEW NEEDED: draft-ietf-v6ops-ent-analysis-00.txt (fwd)

[Tim Chown <tjc@ecs.soton.ac.uk>]

On Thu, Oct 14, 2004 at 06:33:26PM +0300, Heikki Vatiainen wrote:
> 
> I agree that one size does not fit all.  My point was to remind that
> if no IPv6-capable existing routing infrastructure is available, one
> simple possibility is to consider upgrading to such an infrastructure.
> This is what section 4.4 or its subsections are not currently
> mentioning.  Currently the draft makes building parallel IPv6
> infrastructure to look fairly simple when I think it is not.

But 4.2 and 4.3 state this reasonably clearly?   Perhaps removing
the word "existing" would make it clearer?
 
> My current opinion is to prefer upgrade to dual stack over building
> parallel if those are the choices and if there are resources to do the
> both and no special reason to select one over the other. When I wrote
> the original paragraph, I had dual stack vs parallel in mind.

Of course.
 
> Ok, that works for IPv6 Dominant Network Deployment too.  My original
> thought was to reduce the effort by not building parallel infra.  One
> way to achieve that is to go IPv6 dominant.  I have to admit I did not
> think IPv6 Dominant very much when reading the draft since it feels
> like a option that is very much in the future.

Our (my) view is to deploy dual-stack with IPv6 capbility in all (or as
much as possible) of the infrastructure to enable IPv6-only nodes to
be deployed, and a gradual phase over to IPv6 dominant.   

However, one scenario in the analysis is IPv6 dominant from the start,
and so we must cater for that too.
  
> If we would route IPv6 between all or even most of the
> VLANs with a "router-on-a-stick" method, we would have to give up this
> VLAN locality and that would cause plenty of resistance.  It is not
> seen as simple and secure to have all VLANs available on every campus
> Ethernet switch.

And there will be some equipment that does not support VLANs, so it is
not a perfect solution by any means.  But for some (many?) people it will
be good enough (the method is widely used in those European universities 
that are deploying IPv6).
 
> > Hmm we assumed no IPv6 only anything?  But rather use of IPv6 dominantly
> > over IPv4?
> 
> I was thinking IPv6 only router when building a parallel IPv6
> network. The first paragraph of section 4.4.2 mentions the possibility
> of IPv6 only routing.

Yes, that is what we do.   As a bonus we also gain experience in IPv6-only
networking for future wider deployment.
 
> We took a commercial router, as opposed to using a linux or bsd
> router, and experimented with building parallel IPv6 routing using a
> router that has IPv4 routing disabled.  IPv6 routing works very well,
> but the router management was quite heavily tied to IPv4.

Yes, this is the case with many commercial products today (but not all!)
and is an issue to be resolved in due time.
 
-- 
Tim