Subject: [homenet] Single or Multiple Routing Protocols in Homenet

From: "Liubing (Leo)" <[email-masked]>
Date: Sat, 31 May 2014 11:41:33 +0000

Hi all,

We have an ISIS auto-configuration draft under developing in ISIS WG (draft-liu-isis-auto-conf). Since Homenet/SME networks are one of the main scenarios our draft targets at, and we already have an OSPF-autoconf mechanism available (draft-ietf-ospf-ospfv3-autoconfig), during the isis meeting some people raised the question whether Homenet WG want to support multiple IGP auto-configuration mechanisms.

I checked the meeting minutes of the last Homenet meeting. And found the status of the issue is:
- WG had decided to have both a configuration protocol (HNCP) + a routing protocol
- WG hasn't decided to have only one routing protocol or two, or even N...
- it seems only one routing protocol has more support

May I ask a couple of questions:

1) Is it necessary to enforce only one routing protocol?
If HNCP is adopted, I guess multiple routing protocols could be easily supported ?
I think it might be more flexible if homenet router support multiple routing protocols. Is there any harm? 
(Note: supporting multiple routing protocols here doesn't mean they need run at the same time, just more choices.)

2) If we decide to have only one, then what is the criteria for protocol selection?

Look forward to your comments. Many thanks.

Best regards,
Bing

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From: Sander Steffann <[email-masked]>
Date: Sat, 31 May 2014 14:35:00 +0200

Hi,

> (Note: supporting multiple routing protocols here doesn't mean they need run at the same time, just more choices.)

No, it does mean that everybody suddenly has to implement multiple protocols. In a homenet devices must *just work*. Burdening the home user with such choices doesn't make sense. And it means that when there are multiple protocols to choose from the devices will have to implement all of them. Having multiple protocols to support makes the implementors work much harder.

This is a VERY bad idea.
Sander

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From: Gert Doering <[email-masked]>
Date: Sat, 31 May 2014 14:42:39 +0200

Hi,

> (Note: supporting multiple routing protocols here doesn't mean they need run at the same time, just more choices.)

"More protocols" means "more interoperability testing" and "more combinations
of vendor products that suddenly do not interoperate, even if they should".

So I'd keep the list of supported protocols as small as possible - and stick
to IP protocols.  ISIS is great for ISP environments, but does not nicely
adapt to a unix environment where the kernel has no idea about ISO/OSI
protocols and you have to do everything via raw sockets.  Which would be
a fairly typical environment for a CPE router.

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

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From: "Leddy, John" <[email-masked]>
Date: Sat, 31 May 2014 13:11:31 +0000

In the past, and rumblings now, there was some push to enable ISIS over
IPV6.

Independent of Homenet, I think the investigation will continue.

John

On 5/31/14, 8:42 AM, "Gert Doering" <[email-masked]> wrote:

>> (Note: supporting multiple routing protocols here doesn't mean they
>>need run at the same time, just more choices.)
>
>_______________________________________________
>homenet mailing list
>[email-masked]
>https://www.ietf.org/mailman/listinfo/homenet

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From: Gert Doering <[email-masked]>
Date: Sat, 31 May 2014 15:20:30 +0200

Hi,

> Independent of Homenet, I think the investigation will continue.

So, then, we'll have one link-state protocol that runs over IPv6 and
can transport opaque LSAs for arbitrary address families, and one other
link-state protocol that runs over IPv6 and can transport opaque LSAs
for arbitrary address families.  Yes, this is quite obviously going to
be a big win.

Gert Doering
        -- NetMaster

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From: Mikael Abrahamsson <[email-masked]>
Date: Sat, 31 May 2014 18:33:45 +0200 (CEST)

On Sat, 31 May 2014, Gert Doering wrote:

> So I'd keep the list of supported protocols as small as possible - and 
> stick to IP protocols.  ISIS is great for ISP environments, but does not 
> nicely adapt to a unix environment where the kernel has no idea about 
> ISO/OSI protocols and you have to do everything via raw sockets.  Which 
> would be a fairly typical environment for a CPE router.

This is actually a feature, the fact that ISIS doesn't require IPv6 to be 
up and running before it can get itself started and you know the topology 
of the home.

How one values this feature is obviously up to each individual.

Oh, and the other email you sent. Irony doesn't help make your point. That 
email was quite confusing about what point you were actually trying to 
make.

-- 
Mikael Abrahamsson    email: [email-masked]

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From: Gert Doering <[email-masked]>
Date: Sat, 31 May 2014 20:03:43 +0200

Hi,

> up and running before it can get itself started and you know the topology 

Uh, what?  So the benefit of ISIS (over ISO/OSI transport) in the home would 
be "you can have IPv4 in your homenet, without having IPv6"?  I truly can't 
see a reason why this would be useful in the time frame when this would be
ready - and it's also out of scope of what the homenet architecture concerns 
itself with.  Which, as far as I understand, is "make IPv6 work right, and 
do not damage IPv4", while excluding IPv4-only scenarios.

> email was quite confusing about what point you were actually trying to 

Then it was quite clear: I can't see a point in doing protocol work to
solve something in a fashion that would be very very very similar to an
already-existing protocol that has mature implementations.

Gert Doering
        -- NetMaster

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From: Mikael Abrahamsson <[email-masked]>
Date: Sat, 31 May 2014 21:16:44 +0200 (CEST)

On Sat, 31 May 2014, Gert Doering wrote:

> be "you can have IPv4 in your homenet, without having IPv6"?

No, that's not what I said and not what I intended.

You can do topology and router discovery without needing IPv4 or IPv6 
running if you use ISIS.

> already-existing protocol that has mature implementations.

And what protocol are you referring to? Babel? OSPFv3? RIPv2? I can guess 
you're referring to OSPFv3 since you're now saying "similar" (which wasn't 
in your earlier email), but I don't understand why you feel the need for 
irony and need the reader to guess instead of just saying what you mean.

---

From: Douglas Otis <[email-masked]>
Date: Sat, 31 May 2014 12:17:16 -0700

> do not damage IPv4", while excluding IPv4-only scenarios.

Dear Gert,

I could be wrong, but I don't think that was the point. There are also layer 2 protocols to consider.

Expecting everything to be handled at IP transport layer 3 will confront extremely difficult security issues.

Testing using a modern printer/scanner illustrated a major problem when devices were not restricted to link-local.  Something like RBridge supporting PPP would provide a much safer foundation upon which to build. 

All networks must begin with layer 2 starting points.  Selective routing between Rbridges would allow an ability to share data between HDCP enforced multi-media display devices using link-local addresses.  There will be video cameras, baby monitors, HVAC/SCADA controls, printers and scanners offering media stick access, etc. These devices were never intended to directly interface with the Internet.  These devices MUST NOT be assigned routable IPv4 or IPv6 addresses.  Using mDNS proxy into DNS would be setting the stage for major security disasters.

Regards,
Douglas Otis

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From: Juliusz Chroboczek <[email-masked]>
Date: Sat, 31 May 2014 22:03:44 +0200

>> ISIS is great for ISP environments, but does not nicely adapt to a unix
>> environment where the kernel has no idea about ISO/OSI protocols and
>> you have to do everything via raw sockets.

> up and running before it can get itself started

While I happen to like the elegant way ISIS is layered directly over 
layer 2, the practical advantage is mostly gone with IPv6, where routers
communicate using link-local addresses.  For what it's worth, Babel is
quite able to establish adjacencies before addressing is up as well as in
pure IPv4 networks.

(I still think that the ISIS approach is more elegant, though.  But
unfortunately it breaks down once you start including link layers that
cannot easily carry layer 2 frames, such as GRE tunnels.)

-- Juliusz

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From: "Leddy, John" <[email-masked]>
Date: Sat, 31 May 2014 20:57:16 +0000

I like ISIS over V6 as the option.  Just carry V4 info.

But for anyone that wants to run IPX, DecNet, Appletalk, Banyon VinesŠ

You could do ISIS on L2 and carry all the AFI/SAFI info without requiring
V6.

A good solution,

john

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From: Gert Doering <[email-masked]>
Date: Sat, 31 May 2014 23:39:53 +0200

Hi,

> You can do topology and router discovery without needing IPv4 or IPv6 

True, but for what purpose?  Maybe I'm a bit daft today, but I cannot see
the scenario where this would be useful.

If I'm going to do IPv6 "later on", I'm not really sure how much you're
going to win by running ISIS "right away, before IPv6 is running" - and
as you say, you don't intend to be not running IPv6 at all.  So what?

[ different thread ]
> irony and need the reader to guess instead of just saying what you mean.

Oh well.  Maybe my irony detector needs recalibration.  I thought it was
absolutely obvious from the context of "link state protocol" and "transports
opaque LSAs" (plus "a new protocol very much like an existing protocol")
that only OSPFv3 would fill that niche.  RIPv2 is most certainly not a 
link state protocol...

Yes, I didn't say "similar", because I wrote a sentence that repeated the
same thing twice.  Which implies "quite similar".

But oh well, I'll refraim from trying to use humor to bring across a message
that should have been obvious in the first place.

Gert Doering
        -- NetMaster

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From: Gert Doering <[email-masked]>
Date: Sat, 31 May 2014 23:41:45 +0200

Hi,

On Sat, May 31, 2014 at 08:57:16PM +0000, Leddy, John wrote:
> But for anyone that wants to run IPX, DecNet, Appletalk, Banyon Vines?

In *homenet*?

Gert Doering
        -- NetMaster

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From: Gert Doering <[email-masked]>
Date: Sat, 31 May 2014 23:48:32 +0200

Hi,

> >>> would be a fairly typical environment for a CPE router.
[..]
> I could be wrong, but I don't think that was the point. There are also layer 2 protocols to consider.

I quoted my original comment above.  This is the context we're talking
about: protocols to be considered for routing inside the homenet.

In *homenet*.

> All networks must begin with layer 2 starting points.  Selective routing between Rbridges would allow an ability to share data between HDCP enforced multi-media display devices using link-local add…

While this is all true, I cannot see how this related to what I said
above, and to the question of "is ISIS better suited as a link-state
protocol to transport opaque LSAs than OSPFv3?" - because *both* do that
job without "assigned routable IPv4 or IPv6 addresses" - ISIS talks over
L2 (or potentially IPv6 link-local as was mentioned), OSPFv3 talks over 
IPv6 link-local.

This thread wasn't about questioning the whole homenet architecture, but
about a specific side aspect: would additional routing protocols be considered
a plus.  And I say "no", out of general reasoning, and because I consider
the particular protocol to be not very well suited for typical SoHo router
implementations.

Gert Doering
        -- NetMaster