Subject: Re: question: forcing IPV6 traffic down a IPV6/IPV4 tunnel
To: None <itojun@iijlab.net>
From: Robert Elz <kre@munnari.OZ.AU>
List: tech-net
Date: 03/11/2000 18:36:07
    Date:        Sat, 11 Mar 2000 05:38:24 +0900
    From:        itojun@iijlab.net
    Message-ID:  <2243.952720704@coconut.itojun.org>

  | 	Robert, what you are stating is not really dependent to IPv6.
  | 	Whenever you renumber, static route configuration will become invalid,
  | 	regardless from IPv4 or IPv6.

That's certainly true - but no-one has ever pretended that renumbering
an IPv4 site is easy, or should be easy (ie: that that is the way things
are intended to be in the system provided, as opposed to the "it would be
nice if..." meaning of "should")

But one of the prime aims of IPv6 is that renumbering is supposed to be
easy.

Go read the first sentence of section 3 of rfc1900.
That's what we're supposed to be aiming towards.

  | 	So, running a routing daemon is the right answer.

I don't believe that running a routing daemon on a host is the right
answer (to any problem).  The excuses people use for running routed on
IPv4 hosts are all irrelevant in IPv6 (since RA packets exist).   And
while it certainly is on a router, there are times (as in the one
postulated) where outside factors just make it impossible.

  | >(Listening to router advertizements, for end nodes, works fine with
  | > NetBSD.)

Yes, when RAs are being sent, they're just fine.

  | >When you are a _router_ (and you are, when you set up a tunnel!),

No you're not.   You're only a router if you take packets from the
tunnel and send them to some other systems or networks.   Consider your
average single PC at home, running IPv6 PPP to their ISP, and with an
IPv6 tunnel to their nearest IPv6 provider (and no NICs in their box at all).

Who would they be being a router for?

  | 	If you are wondering about IPv6 ISP does: IIJ is exchanging route
  | 	with customer (/48), with filtering for inbonud routes.

This is fine if your provider does it.   My IPv6 provider does static
routing only.   Fortunately I'm not using NetBSD (or KAME) as the end
point of a tunnel, I'm using a router that does let me set a default
route to point to an interface (a tunnel interface in this case).

kre