Re: Distributing site-wide RFC 3484 policy

[Arifumi Matsumoto <arifumi@nttv6.net>]

Jun-ichiro itojun Hagino wrote:
> > I understood your opinion in one sense, but there might have been  
> > problematic cases with reality.
> >
> > some part are same as Brian, and we has been tried to write in the  
> > Problem statement
> >
> > - Currently we already have coexistence of VPN access and Global  
> > Internet Access in a site
>
> 	as i respnoded to Brian this is a non-issue.

I replied about this point in another email.

> > - demands for controlling prefixes exists in some cases
>
> 	this has to be done sorely with routing table using ip6_dst, nothing
> 	else.  if you use ip6_src for controlling routing, you will go into
> 	paradise of "policy routing" that is, basicaly, a pitfall towards hell.

I think you've already mentioned the benefit of policy routing, haven't 
you ? As far as the source address is used for some reasons, such as
routing and access control, I believe there should be demand for control
the source address to be chosen.

> > - demands for controlling v4-v6 preference
>
> 	maybe, but what would you need more than "IPv6 then IPv4"?

At least, I know there is a motivation for smooth transition
to IPv6, such as,
IPv4 only
 -> IPv4 and IPv6 with lower preference
  -> IPv4 and IPv6 with higher preference
   -> IPv6 only.

Another case may be a network administrator knows that the
quality of IPv6 connectivity is clearly worse than that of
IPv4 because of tunneling or something.