[124074] in North American Network Operators' Group
Re: IP4 Space
daemon@ATHENA.MIT.EDU (Christopher Morrow)
Mon Mar 22 20:43:05 2010
In-Reply-To: <5F1787CD-3F1D-481A-86F7-4310C8559797@academ.com>
Date: Mon, 22 Mar 2010 17:42:31 -0700
From: Christopher Morrow <morrowc.lists@gmail.com>
To: Stan Barber <sob@academ.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mon, Mar 22, 2010 at 3:53 PM, Stan Barber <sob@academ.com> wrote:
> In this case, I am talking about an IPv6<->IPv6 NAT analogue to the curre=
nt IPv4<->IPv4
> NAT that is widely used with residential Internet service delivery today.
I don't necessarily see 6-6 nat being used as 4-4 is today, but I do
think you'll see 6-6 nat in places. the current ietf draft for 'simple
cpe security' (draft-ietf-v6ops-cpe-simple-security-09.txt) is
potentially calling for some measures like nat, not nat today but...
> I believe that with IPv6 having much larger pool of addresses and each re=
sidential
> customer getting a large chunk of addresses will make =A0IPv6<->IPv6 NAT =
unnecessary. I
> also believe that there will be IPv6 applications that require end-to-end=
communications
> that would be broken where NAT of that type used. Generally speaking, man=
y users of
I think you'll see apps like this die... quickly, but that's just my opinio=
n.
> the Internet today have not had the luxury to experience the end-to-end m=
odel because of
> the wide use of NAT.
>
> Given that these customers today don't routinely multihome =A0today, I cu=
rrently believe
> that behavior will continue. Multihoming is generally more complicated an=
d expensive
That's not obvious. if a low-cost (low pain, low price) means to
multihome became available I'm sure it'd change... things like
shim-6/mip-6 could do this.
> than just having a single connection with a default route and most reside=
ntial customers
> don't have the time, expertise or financial support to do that. So, the r=
ate of multihoming
> will stay about the same even though the number of potential sites that c=
ould multihome
> could increase dramatically as IPv6 takes hold.
>
> Now, there are clearly lots of specifics here that may change over time c=
oncerning what
> the minimum prefix length for IPv6 advertisements might be acceptable in =
the DFZ (some
> want that to be /32, other are ok with something longer). I don't know ho=
w that will change
> over time. I also think that that peering will continue to increase and t=
hat the prefix
> lengths that peers will exchange with each other are and will continue to=
be less
> constrained by the conventions of the DFZ since the whole point of peerin=
g is to be
> mutually beneficial to those two peers and their customers. But, that bei=
ng said, I don't
> think residential customers will routinely do native IPv6 peering either.=
I think IP6-in-IPv4
> tunneling is and will continue to be popular and that already makes for s=
ome interesting
> IPv6 routing concerns.
I firmly hope that ipv6-in-ipv4 dies... tunnel mtu problems are
horrific to debug.
(we'll see though!)
-chris
> Hope that clarifies my comment for you. Obviously, they are my opinions, =
not facts. The
> future will determine if I was seeing clearly or was mistaken in how thes=
e things might
> unfold. However, I think a discourse about these possibilities is helpful=
in driving
> consensus and that's one of the valuable things about mailing lists like =
this.
>
>
> On Mar 18, 2010, at 8:20 PM, Christopher Morrow wrote:
>
>> On Thu, Mar 18, 2010 at 7:36 PM, Stan Barber <sob@academ.com> wrote:
>>> Ok. Let's get back to some basics to be sure we are talking about the s=
ame things.
>>>
>>> =A0First, do you believe that a residential customer of an ISP will get=
an IPv6 /56 assigned for use in their home? Do
>>> you believe that residential customer will often choose to multihome us=
ing that prefix? Do you believe that on an
>>> Internet that has its primary layer 3 protocol is IPv6 that a residenti=
al customer will still desire to do NAT for reaching
>>
>> how are nat and ipv6 and multihoming related here? (also 'that has a
>> primary layer 3 protocol as ipv6' ... that's a LONG ways off)
>>
>> -chris
>>
>>> IPv6 destinations?
>>>
>>> I am looking forward to your response.
>>>
>>>
>>>
>>>
>>> On Mar 18, 2010, at 2:25 PM, William Herrin wrote:
>>>
>>>>> On Mar 5, 2010, at 7:24 AM, William Herrin wrote:
>>>>>> Joel made a remarkable assertion
>>>>>> that non-aggregable assignments to end users, the ones still needed
>>>>>> for multihoming, would go down under IPv6. I wondered about his
>>>>>> reasoning. Stan then offered the surprising clarification that a
>>>>>> reduction in the use of NAT would naturally result in a reduction of
>>>>>> multihoming.
>>>>
>>>> On Thu, Mar 18, 2010 at 11:07 AM, Stan Barber <sob@academ.com> wrote:
>>>>> I was not trying to say there would be a reduction in multihoming. I =
was
>>>>> trying to say that the rate of increase in non-NATed single-homing
>>>>> would increase faster than multihoming. I guess I was not very clear.
>>>>
>>>>
>>>> Hi Stan,
>>>>
>>>> Your logic still escapes me. Network-wise there's not a lot of
>>>> difference between a single-homed =A0IPv4 /32 and a single-homed IPv6
>>>> /56. Host-wise there may be a difference but why would you expect that
>>>> to impact networks?
>>>>
>>>> Regards,
>>>> Bill Herrin
>>>>
>>>>
>>>>
>>>> --
>>>> William D. Herrin ................ herrin@dirtside.com =A0bill@herrin.=
us
>>>> 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
>>>> Falls Church, VA 22042-3004
>>>
>>>
>>>
>
>
