Subject: [homenet] Does ND Proxy useful for homenet?

From: Shishio Tsuchiya <[email-masked]>
Date: Sun, 09 Oct 2011 07:16:38 +0900

Hi
I was considering whether ND proxy would be useful for homenet environment,when Fred's presentation.
http://trac.tools.ietf.org/wg/homenet/trac/raw-attachment/wiki/WikiStart/Homenet Routing.pdf

The reason are
-address usage efficiency
2^64 host address space would be too enough for homenet.
-prefix delegation
ND proxy does not require delegate prefix to upstream router.
-Security
ND proxy would be security point.
-running code
ND proxy(RFC4389) is experimental,but there is running code.
http://tools.ietf.org/html/rfc4389
Especially in Japan,some vendors(maybe 2 or 3) already supported very similar function as RA proxy.
As you may know,NTT East/West has been assigned IPv6 address for their wall garden since Feb. 2007.
CPE supports this by two method.
-Ether-type(0x86DD) bridge,it called IPv6 path-though
-RA Proxy

RA proxy router can inspect of IPv6 data packets as theoretical.

I would appreciate any comments.

Regards,
-Shishio

---

From: Shishio Tsuchiya <[email-masked]>
Date: Mon, 10 Oct 2011 07:41:19 +0900

Ups.
Sorry please discard this mail.
I made this mail,before current discussion.

(2011/10/09 7:16), Shishio Tsuchiya (shtsuchi) wrote:
> _______________________________________________
> homenet mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/homenet
>

---

From: Mikael Abrahamsson <[email-masked]>
Date: Mon, 10 Oct 2011 08:16:17 +0200 (CEST)

> 2^64 host address space would be too enough for homenet.

I would just like to comment on this even though you retracted your 
question.

As an ISP, I do not want to participate in a home with hundreds or 
thousands of active IPv6 addresses that I need to keep state for. Most 
likely, when we have central equipment participating in a home network, 
we'll implement a limit on number of neighbours it'll allow on the subnet. 
Doing ND/NS a lot takes resources.

If customer wants to use more IPv6 addresses, we'll require them to get a 
home router and PD address space to it to distribute the ND/NS load.

-- 
Mikael Abrahamsson    email: [email-masked]

---

From: Cameron Byrne <[email-masked]>
Date: Mon, 10 Oct 2011 07:06:50 -0700

question.

Agreed. But I think it is worth noting that nd-proxy is  practical in mobile
networks where each subscriber gets a unique /64.

Mobile network attachment has popped up a few times in homenet discussions.

Cb

---

From: Victor Kuarsingh <[email-masked]>
Date: Mon, 10 Oct 2011 10:25:54 -0400

>> I would just like to comment on this even though you retracted your question.
>>
>> As an ISP, I do not want to participate in a home with hundreds or thousands
of active IPv6 addresses that I need to keep state for. Most likely, when we
have central equipment participating in a home network, we'll implement a limit
on number of neighbours it'll allow on the subnet. Doing ND/NS a lot takes
resources.

>Mobile network attachment has popped up a few times in homenet discussions.

Yes, this will useful in a number of use cases with mobile attachment.
Tethering and other like operations come to mind.
A good reference is - draft-ietf-v6ops-3gpp-eps for mobile operation.

Victor K

>Cb
_______________________________________________ homenet mailing list
[email-masked] https://www.ietf.org/mailman/listinfo/homenet

---

From: Mikael Abrahamsson <[email-masked]>
Date: Mon, 10 Oct 2011 19:38:51 +0200 (CEST)

On Mon, 10 Oct 2011, Cameron Byrne wrote:

> Agreed. But I think it is worth noting that nd-proxy is practical in 
> mobile networks where each subscriber gets a unique /64.
>

I think ND proxy has some use even in other cases, I would just like to be 
sure that there is consensus that this won't scale to a home with lots and 
lots of devices. The number 10 or 16 simulatenous active IPv6 addresses 
comes to mind, after that I don't want to know what they have in their 
home anymore, they'll have to route it themselves.

---

From: Michael Richardson <[email-masked]>
Date: Mon, 10 Oct 2011 15:41:11 -0400

>>>>> "Mikael" == Mikael Abrahamsson <[email-masked]> writes:
    >> Agreed. But I think it is worth noting that nd-proxy is practical
    >> in mobile networks where each subscriber gets a unique /64.
    >> 

    Mikael> I think ND proxy has some use even in other cases, I would
    Mikael> just like to be sure that there is consensus that this won't
    Mikael> scale to a home with lots and lots of devices. The number 10
    Mikael> or 16 simulatenous active IPv6 addresses comes to mind,
    Mikael> after that I don't want to know what they have in their home
    Mikael> anymore, they'll have to route it themselves.

So, I think that most of us were thinking that proxy-ND is what the home
does when the home runs out of it's /60.  I don't see why the ISP would
ever see this.   

Or are you saying a mobile device (a smartphone) will only ever get a
/64 to share?

-- 
]       He who is tired of Weird Al is tired of life!           |  firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net architect[
] [email-masked] http://www.sandelman.ottawa.on.ca/ |device driver[
   Kyoto Plus: watch the video <http://www.youtube.com/watch?v=kzx1ycLXQSE>
	               then sign the petition.

---

From: Cameron Byrne <[email-masked]>
Date: Mon, 10 Oct 2011 12:59:39 -0700

On Mon, Oct 10, 2011 at 12:41 PM, Michael Richardson <[email-masked]> wrote:
>    >> Agreed. But I think it is worth noting that nd-proxy is practical
>    >> in mobile networks where each subscriber gets a unique /64.
>    >>
>    >> Mobile network attachment has popped up a few times in homenet
>    >> discussions.
>

Today, yes.  GSM/UMTS/LTE devices today only support local /64 from
the mobile network, AFAIK... and I have seen implementations of ND
Proxy.  I have not seen anything aside from providing one network
provided IPv4 address per mobile device (then the mobile will do its
own NAT44 of that address)... but i may just be missing something
there.  My infrastructure is only setup to provide 1 IPv4 address
and/or 1 /64 of IPv6.

Some future spec's from 3GPP will allow for DHCPv6-PD, but that is
forthcoming standards work and implementations.

Cameron

---

From: Mark Townsley <[email-masked]>
Date: Mon, 10 Oct 2011 16:01:03 -0400

> Or are you saying a mobile device (a smartphone) will only ever get a

My (limited) understanding of the various 3/4G standards are that a PD for a phone is something that is very, very, recent. Perhaps Rajeev (cc'd) or someone else here can elucidate. 

- Mark

---

From: Mark Townsley <[email-masked]>
Date: Mon, 10 Oct 2011 16:04:15 -0400

> forthcoming standards work and implementations.

Cameron not only beat me with an answer, he provided a more informed one. Thanks!

- Mark

---

From: Curtis Villamizar <[email-masked]>
Date: Mon, 10 Oct 2011 14:24:04 -0700

In message <[email-masked]>
 
> home router and PD address space to it to distribute the ND/NS load.

+1
violent agreement, etc

IMO the ground rules are: The ISP provides one prefix.  The homenet
subdivides it only if there are multiple subnets.  The ISP doesn't see
the longer prefixes that exist only within the homenet.

Curtis

---

From: "Joel M. Halpern" <[email-masked]>
Date: Mon, 10 Oct 2011 20:56:56 -0400

Curtis, I would not call what you describe "ground rules."  They are a 
valid and useful operating premise, used by many residential service 
providers.
Other service providers prefrer other architectures and state 
maintenance, in exchange for other capabilities.

While I would not want to insist that all edge home routers must be 
bridges, I find it unfortunate that folks seem to be insisting that they 
must be routers.

Yours,
Joel M. Halpern

On 10/10/2011 5:24 PM, Curtis Villamizar wrote:
>
> In message<[email-masked]>

---

From: Rajeev Koodli <[email-masked]>
Date: Mon, 10 Oct 2011 13:51:23 -0700

Hi,

The smartphone will only get a /64 in the current 3G/4G releases (rel-8,
rel-9).

Prefix delegation is specified in Rel-10.

-Rajeev

On 10/10/11 1:01 PM, "Mark Townsley" <[email-masked]> wrote:

> My (limited) understanding of the various 3/4G standards are that a PD for a
> phone is something that is very, very, recent. Perhaps Rajeev (cc'd) or
> someone else here can elucidate.
> 
> - Mark
>

---

From: Victor Kuarsingh <[email-masked]>
Date: Wed, 12 Oct 2011 12:04:53 -0400

Mark,

A few points on this topic.

As noted, the Cell system will have PD capabilities until a future 3GPP
release (Rel-10) as noted.  Although, even when the functionality is in
place (generally), small devices like Smartphone and the mini gateways
(3G/LTE devices which allow for 4-5 hosts to attached to Cell system) -
PDs may not be used.

Many of these devices (I.e in the case of the smartphone) have modes of
operation where they "tether", which turns them into a mini gateway.  They
are not likely to be be full blown gateways equivalent to what you see
common CPEs.

In the IPv4 case, these devices "NAT" the IPv4 private addresses used by
hosts behind the device to the network assigned address.  In the case of
IPv6, it will have access to the network assigned ::/64.  PCs (maybe other
devices) behind such devices will need access to the IPv6 network, but may
not have access to PD space.  This was one of the specific use cases I was
eluding to before.

These devices (in such operating modes) are however not likely to
participate in a home network (as the gateway device or a router) and it's
very unlikely to be the head of home network.

With this explanation, I am not sure if this should/would be considered as
such in HomeNet.  These devices technically become gateways/bridges to the
Internet.  And the hosts that use them are often the same type of devices
which connect to common home networks.

Regards,

Victor K

---

From: Michael Richardson <[email-masked]>
Date: Wed, 12 Oct 2011 20:41:36 -0400

>>>>> "Victor" == Victor Kuarsingh <[email-masked]> writes:
    Victor> These devices (in such operating modes) are however not
    Victor> likely to participate in a home network (as the gateway
    Victor> device or a router) and it's very unlikely to be the head of
    Victor> home network.

I STRONGLY DISAGREE.

Not only will smartphones be pressed into use whenever the primary ISP
is down (I've done this three times in 18 months since I got a
smartphone), but whenever there is an ad-hoc gathering of people who
need network, they will insist that their smartphones be smart. 

I expect my smartphone to provide network to my Personal Area Network
(whether via Bluetooth PAN or Zigbee), and I further expect that PAN to
have an alternate exit via my HAN.

I want to further point out that 3GPP and the mobile operators are no
longer in control of what phones do.  They are network devices.  The
only thing they can control is the protocol on the wire, and if they
piss of the consumer, the consumer will simply tunnel.

It's good that 3G will have PD in the future.
I know that new versions of SIXXS AICCU now include it.

---

From: Curtis Villamizar <[email-masked]>
Date: Wed, 12 Oct 2011 20:04:51 -0700

In message <[email-masked]>
 
> which connect to common home networks.

Victor,

And if I'm at home with WiFi at home and my laptop plugged into the
Internet and plug in the USB (or other tether) to update my contacts
list on the phone, because its easier/faster, we have the situation
described, even though the intent was not to use the phone as an IP
gateway.

This gets back to users plugging things in in seemingly arbitrary way
that made sense to them at the time for some reason.

Curtis

---

From: Victor Kuarsingh <[email-masked]>
Date: Wed, 12 Oct 2011 23:38:31 -0400

>    Victor> device or a router) and it's very unlikely to be the head of

That's fine. My statement was based on an aggregate set of behaviors over
millions of endpoints.  Corner cases always exist (and perhaps not so corner
in the future).

> need network, they will insist that their smartphones be smart.

Sure, a number of people seem to do this and tether their phones for
Internet Access.  Although performance is
somewhat degraded as Smartphones don't seem to make very good routers
(performance wise - but this may change).  Notice I did not say "never", I
said "not likely".

> have an alternate exit via my HAN.

Understood.  However is that what most people will expect?  Perhaps one can
argue yes.

> longer in control of what phones do.  They are network devices.

I guess this is true to some extent.  There is value in having standards in
this area which make things work in a relatively complex environment.

>  The

I guess some may tunnel.  Not sure if most would.

> I know that new versions of SIXXS AICCU now include it.
PD is in the spec.  But when it sees the light of day in actual deployments
(network + devices) is the key.

regards,

Victor K

--

---

From: Victor Kuarsingh <[email-masked]>
Date: Wed, 12 Oct 2011 23:48:32 -0400

> described, even though the intent was not to use the phone as an IP

I can see your point. So in this case.. I guess your computer/laptop would
belong to two networks (wired USB and Home Network over WiFi).  Not sure if
this example shows how the two networks join - unless the computer
bridges/routes traffic.

> that made sense to them at the time for some reason.

Would you say this example adds merits to ND for the smartphone gateway
function, or the opposite?

regards,

Victor K

---

From: Curtis Villamizar <[email-masked]>
Date: Wed, 12 Oct 2011 21:37:44 -0700

In message <CADiurz38Hq4+xxYhx+s7XDOOv5rsaKxGnNj=[email-masked]>
Victor Kuarsingh writes:
> I can see your point. So in this case.. I guess your computer/laptop
> would belong to two networks (wired USB and Home Network over WiFi).
> Not sure if this example shows how the two networks join - unless the
> computer bridges/routes traffic.

Good point.  The computer would have three ways to pick from.

Maybe the phone acting as a WiFi was a better example.

> Would you say this example adds merits to ND for the smartphone
> gateway function, or the opposite?

ND just finds the link local addresses.  Figuring out which way to go
with packets is another story.

You need a routing protocol if there is a loss of connectivity more
than one hop away.  At that point the addresses are still valid, but
the path to the default route has changed.

There is no fast withdraw in ARP proxy, DHCP proxy, ND proxy.  In a
routing protocol, the flooding of bad news is fast.  Plus arbitrary
topologies can be supported.

And as Jim pointed out, we need to be careful about the scalability of
flooding for WiFi networks that may be come dense.

Regards,

Curtis

---

From: "Pascal Thubert (pthubert)" <[email-masked]>
Date: Thu, 13 Oct 2011 07:33:08 +0200

+1

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of Michael Richardson
Sent: jeudi 13 octobre 2011 02:42
To: [email-masked]
Subject: Re: [homenet] Does ND Proxy useful for homenet?

I STRONGLY DISAGREE.

-- 
]       He who is tired of Weird Al is tired of life!           |
firewalls  [
]   Michael Richardson, Sandelman Software Works, Ottawa, ON    |net
architect[
] [email-masked] http://www.sandelman.ottawa.on.ca/ |device
driver[
   Kyoto Plus: watch the video
<http://www.youtube.com/watch?v=kzx1ycLXQSE>
	               then sign the petition. 
_______________________________________________
homenet mailing list
[email-masked]
https://www.ietf.org/mailman/listinfo/homenet

---

From: Russ White <[email-masked]>
Date: Thu, 13 Oct 2011 07:49:38 -0400

>     >>>>> "Victor" == Victor Kuarsingh <[email-masked]
>     <mailto:[email-masked]>> writes:
> That's fine. My statement was based on an aggregate set of behaviors
> over millions of endpoints.  Corner cases always exist (and perhaps not
> so corner in the future).

This won't be the "corner case," it will be the "common case," in most
all homes. The electricity providers are seeing to that right now, as
well as the cell phone providers. In a few years, someone is going to
say, "you only have one internet connection? You poor soul, we need to
find some government program to help you."

:-)

Russ

---

From: Victor Kuarsingh <[email-masked]>
Date: Thu, 13 Oct 2011 20:57:20 -0400

>find some government program to help you."

Russ, I agree the mobile network will be used widely in home networks by
the residential and business customers (as you noted electricity
providers).  Although I would suppose those connections will not be using
cell phones for connectivity, but more gateway style devices with a
2G/3G/4G connection.  Most of these devices tend to be somewhat stationary
(I.e. Meters, parking kiosks, etc).  Some devices are nomadic but those
tend to be end points themselves with built in radios.

The corner case I was talking about was the use of a smartphone (generally
nomadic device) as a gateway with the expectation that when at home
becomes an active part of the home network fabric and exchanges routing
information.  When the person turns off their phone, leaves the house, etc
- the device would then be removed from the network (assuming it attached
in the first place).

Assuming for now that this will be common case (my iPHone/Android Phone is
part of my home network when I show up at home and then disappears when I
leave) - I would have some concerns if this was all automatic with
absolutely no user intervention or permission.

I can imagine a use cases where a bunch of friends show up at a house
party and become a mesh network with many attachments to the network
(assuming all automatic and happens without user intervention - as one of
the previous comments had noted was a possibility).  Not sure how that
would work - and I would not want to be the guy who's phone was chosen
(automatically) to be the gateway for all (my bill may be quite large that
month).

All that said, I would likely lean toward the notion that smartphone
vendors, if they make their devices full gateways for such use, would not
just make this fully automatic such that it would happen by accident.  A
simple "do you want to attach to X" popup/message may be warranted.  If
so, then the phone can move from "I am a lone gateway with small local
network mode" to "I am now a router in a larger network" and augment
functions accordingly.

The former case, which is very common now, needs to be addressed (and for
a while may have not PD).  I would not also want to assume that all the
smartphone vendors will build amazing gateways for such uses (vendors who
always maximize CPU/Memory to make sure the user has all the power they
will ever need and never cheap out to squeeze as much profit by lowering
COGs).

I would at minimum assume that some smart phones will be very smart and
may attach to bigger networks (I hope with some type of prompt) and others
will be less smart and built to provide bare minimum gateway
functionality. 

Regards,

Victor K