Subject: Re: (ipv6mh) the Rebel Alliance meetings in Atlanta (long)

From: Kurt Erik Lindqvist <[email-masked]>
Date: Tue, 3 Dec 2002 20:22:55 +0100

(I trimmed the CC list...)

On måndag, dec 2, 2002, at 13:15 Europe/Stockholm, Iljitsch van Beijnum 
wrote:

> On Thu, 28 Nov 2002, Kurt Erik Lindqvist wrote:
>
>>> The main issue is, devise an exit plan before you let stuff pollute 
>>> the
>>> routing tables: part of the consensus should be an agreement on how 
>>> the
>>> advertisements will be limited in the future, so that only very few
>>> sites get advertised that way. For example, maybe we should only 
>>> agree
>>> that a given ISP can only allocate a limited number of "routable 
>>> /48".
>>> Maybe a condition for accepting such a BGP advertisement will be that
>>> the /48 should be of the form xxxx:xxxx:000y, where xxxx:xxxx is the
>>> /32
>>> allocated to the provider -- this would limit inflation to 16 entries
>>> per provider...
>
>> I think that is to few, but the concept is actually pretty nice. Then
>> again, I am not sure it will have much effect.
>
> X per ISP is not going to work as there are global ISPs and very, very
> local ones.

Well, what I meant was that the day an ISP run out of their PI blocks 
they will just continue down the address block, just as ISPs today are 
announcing more specifics than their RIR allocation and complaining 
that these are not accepted. I don't see why we think people would 
behave differently just because this is IPv6....

>> Backing out is simple and will happen on it's own, as is the case 
>> today.
>
> It would be much, much better if we could agree that everyone does this
> the same way. Having a route in 90% of the routers isn't much better
> than having it in 100% of the routers, but being able to reach 90% of
> the internet is much worse than being able to reach 100%.

That is the way it works for many (perhaps most) of the multihomers 
today. 90% is better than the 0% we have today. Still, I agree that if 
we can come up with a common solution that would be better. My proposal 
is to accept /48 for the time being and not scale back until there is a 
new solution.

>
> If geo aggregation isn't feasible, then I think a fixed block of PI 
> /48s
> for each RIR would be the next best option. I think that everyone can
> agree that 4 or 5 x 1024 - 8192 (for a total of 4096 - 40960) routes
> wouldn't be too bad if we can keep a tight lid on this. And if and when
> other blocks are commisioned, people can choose to carry or filter
> those, without hurting existing multihomers.
>

What is it that we think we gain with these specific blocks, be it for 
site-locals or multihoming? The number of routes are not going to be 
less. If the RIRs use up their current assignments -good! Then at least 
we have a IPv6 network from where we can start drawing conclusions. The 
current routing table is mostly 6bone space that is temporary and 
should go away. That leaves us with the ~250 sub-TLAs currently 
assigned. I am not worried yet.

- kurtis -

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Wed, 4 Dec 2002 10:54:11 +0100 (CET)

> (I trimmed the CC list...)

Good, I got some of your messages three times...

> behave differently just because this is IPv6....

We think that because they do. At the moment, at least. Also, we want
them to, as current IPv4 routing practices aren't exactly great. On the
one hand it is good that people want to keep the IPv6 routing table
clean, on the other hand we don't want to be so restrictive it doesn't
work. Remember that most people have a good reason to pollute the IPv4
routing table. Just not allowing this without offering alternatives
isn't good enough.

> today. 90% is better than the 0% we have today.

Disagree. People who multihome care about their connectivity more than
others. For PI, 90% isn't enough. 99% isn't even enough. On the other
hand, for shooting holes in PA, having a 90% backup is probably good
enough, but I'd rather have 99% or even 100%, especially if I have to
eat the cost and annoyance of renumbering when changing my primary ISP.

> Still, I agree that if

I could live with that if we can get consensus among operators. Without
those /48s in the routing table this is still too risky as it doesn't
protect you against an entire ISP going down.

However, I don't think it's the best solution.

Also, if we end up with a multi-address solution, it could very well be
that all PA will be tied to interconnect locations. For instance, I live
between two of the largest exchange points in the world: the LINX and
the AMS-IX. If I were a single homed multi-address capable network I
would want addresses that are always routed over the LINX and also
addresses that are always routed over the AMS-IX, so I can do traffic
engineering.

I'm not saying we should start doing this now, but it would be good to
anticipate future developments.

> > If geo aggregation isn't feasible, then I think a fixed block of PI /48s

> less.

This way you can easily identify these routes with a prefix filter. I'm
not saying that's always absolutely necessary, but as long as we have
the choice, why not create this option?

> If the RIRs use up their current assignments -good! Then at least
> we have a IPv6 network from where we can start drawing conclusions.

Fully agree.

Iljitsch

BTW, I'm writing an article about if/when IPv6 will be adopted for a
Dutch magazine. I'm still looking for good quotes from IPv6-skeptics.  :-)

---

From: Pekka Savola <[email-masked]>
Date: Thu, 5 Dec 2002 09:23:31 +0200 (EET)

> assigned. I am not worried yet.

If PI allocations are from a specific block, advertisements from there can
be denied very easily everywhere in DFZ, leaving just private
arrangements.

-- 
Pekka Savola                 "Tell me of difficulties surmounted,
Netcore Oy                   not those you stumble over and fall"
Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords

---

From: Ronald van der Pol <[email-masked]>
Date: Thu, 5 Dec 2002 11:52:32 +0100

> Dutch magazine. I'm still looking for good quotes from IPv6-skeptics.  :-)

Wrong question. IPv6 *is* being adopted at an exponential rate. See
http://www.nlnetlabs.nl/ipv6/measurements/index.en.html

	rvdp

---

From: Iljitsch van Beijnum <[email-masked]>
Date: Thu, 5 Dec 2002 12:28:37 +0100 (CET)

> http://www.nlnetlabs.nl/ipv6/measurements/index.en.html

I'm not sure what that proves... So the increase in IPv6 ASes is 50 -
100 % a year. At 100%, it will take 6 years for IPv6 to catch up with
IPv4, at 50% it may never happen because of the autonomous growth in
IPv4 ASes. But that's not even very important: as of this week, you may
see AS12854 in the statistics. However, in IPv6 this is usually just a
single box with no real services available: nothing compared with what
you see if you use IPv4.

At the same time, v6 is making progress all the time, and large scale
adoption could happen very quickly, since most of what we need is in
place or getting close. But there's no telling when this will happen.

---

From: Ronald van der Pol <[email-masked]>
Date: Thu, 5 Dec 2002 13:11:49 +0100

On Thu, Dec 05, 2002 at 12:28:37 +0100, Iljitsch van Beijnum wrote:

> I'm not sure what that proves...

It shows that IPv6 is being adopted, the question you asked. You were
not talking about massive deployment or comparing it with IPv4.

	rvdp

---

From: Kurt Erik Lindqvist <[email-masked]>
Date: Fri, 6 Dec 2002 17:23:19 +0100

> routing table. Just not allowing this without offering alternatives

Well, let me restate what I said in Atlanta:

1) We have no idea how popular multihoming is in reality. If it turns 
out my DLS subscriber charges me $50 a month for a single homed 
connection and $500 a month for multihoming this might not be as 
popular as we think. One thing I think we must realize is that a) IPv6 
will be more expensive that IPv4, b) multihoming will not be for free.

2) We don't understand what effects the "better starting point" with 
aggregation will have on the routing table.

What I suggest will give us experience with the above and then we have 
some facts to discuss around. Today we only have wet dreams.

> eat the cost and annoyance of renumbering when changing my primary ISP.

Uhm so you support my proposal then? Makeing it a requirement to accept 
the longer prefixes would help - right?

> protect you against an entire ISP going down.

I don't think the operators are a problem here. Finding enough 
operators to actually connect the customers are a problem, not the 
prefix length.

> addresses that are always routed over the AMS-IX, so I can do traffic

Having been one of the largest operators connected to both AMS-IX and 
Linx, I would not want this. But most people probably agree. I would 
have asked for the traffic flowing over the private peerings.

> the choice, why not create this option?

But if we introduce prefix filters we lost the entire idea of creating 
these in the first place.

> Dutch magazine. I'm still looking for good quotes from IPv6-skeptics.  

I am not necessary an IPv6 sceptic. I just don't think it will give us 
peace in the middle-east. Contact me offline if you want to talk more. 
MY GSM number is in my RIPE object.

- kurtis -

---

From: Kurt Erik Lindqvist <[email-masked]>
Date: Fri, 13 Dec 2002 10:53:58 +0100

> http://www.nlnetlabs.nl/ipv6/measurements/index.en.html

Well, with low enough relative numbers you can make anything grow 
exponentially. :)

- kurtis -