Subject: Re: getting IPv6 space without ARIN (Re: PAT )

From: [email-masked] (Sean Doran)
Date: Thu, 17 Aug 2000 19:37:29 +0200 (CEST)

Itojun -

| First of all, do not cook up IPv6 prefix on your own.  You cannot pick
| random prefix number, that can jeopadize the whole point of experiment.

Could you expand on that please?  So far, I see from Matt Crawford a single
reason (IP6.INT coordination), and that at least should be in the
draft, but I personally would be interested in what the objections
to a random selection of a global address really are.   An aesthetic
argument is fine, as long as it's an explanation of how it "jeapordizes
the whole point of experiment".

> If it is possible, try to contact nearest upstream 6bone site, or
> upstream ISP, to give you an IPv6 prefix

How does one evaluate the nearness of a 6bone site or ISP, so that
one can determine which is nearest?   What if the nearest is uncooperative?

	Sean.

---

From: [email-masked]
Date: Fri, 18 Aug 2000 02:46:26 +0900

not sure if it is fine to continue it here, i may want to move
	to ipngwg.... ietf@ietf looks too wide distribution.

>the whole point of experiment".

	i saw couple of incidents where novice user picked up:
	- multicast address prefix for unicast use (ff00::/8)
	- link-local address prefix for offlink use (fe80::/8)
	- non-standard prefix length (not /64, varies very much)
	and caused too much trouble for them.

	the goal of the draft is to help novice users from going into
	common pitfalls.

>one can determine which is nearest?   What if the nearest is uncooperative?

	usually, 6bone sites connect to your location using IPv6 over IPv4
	tunnel (RFC1933).  for stable operation of the tunnel, it is very	
	important to make IPv4 hops very short.  if you configure a long-haul
	tunnels (like transpacific, or from eastcoast to westcoast across
	different ASes), you will have trouble with stability.

	use IPv4 traceroute to measure the nearness.

	if the nearest is uncooperative (i hope not...), pick the next closest
	one :-)

>>o The site may use the address prefix: 3ffe:0501:ffff::/48.  The address
>>  prefix was curved out from WIDE 6bone prefix.  The site MUST be
>>  renumbered, before the site gets connected to the worldwide IPv6
>>  network.
>Shouldn't IPv6's much-trumpeted stateless autoconfiguration and
>renumbering scheme take care of that, well, automatically?

	the phase-out happens only if the site adminitrator properly configurd
	for that.  we need to put enough warning as we will have major trouble
	if the address leaks out to IPv6 worldwide network (just like
	IPv4 private address leakage).

>How is this different from a completely-disconnected site using
>a randomly selected prefix?

	see above.

itojun