As I understand it, your draft is trying to establish the notion of a multi-hop 
link but
that is not architecturally correct – I think that was the point of the PILC 
comment.

Instead of a multi-hop “link”, what you have is a multi-hop “subnetwork” with
link segments joined together by  subnetwork routing protocols. To establish
a link in the normal sense, configure an NBMA tunnel virtual overlay over the
subnetwork. IPv6 ND and DHCPv6 then work as-expected.

Thanks – Fred
[email protected]

From: [email protected] [mailto:[email protected]] On 
Behalf Of Emmanuel Baccelli
Sent: Monday, January 19, 2015 12:36 PM
To: Joe Touch
Cc: Templin, Fred L; Brian E Carpenter; Alexandru Petrescu; [email protected]
Subject: Re: [Int-area] About draft-baccelli-manet-multihop-communication-04

Hi Joe,

PILC is a great ref that should be cited indeed. Another relevant ref is RFC 
5889. One of the recommendations that RFC boils down to:  *do not* use on-link 
prefixes *at all* on interfaces to multi-hop wireless networks -- the subject 
of the draft we discuss now.

The reason is: there is no planned structure at link-layer and you cannot 
guarantee anything in terms of connectivity over such wireless interfaces -- 
which does not however mean that these interfaces are useless!

In short: this is not yet another simple case of NBMA. Ergo the need for this 
draft.

Best,

Emmanuel

On Fri, Jan 16, 2015 at 9:58 PM, Joe Touch 
<[email protected]<mailto:[email protected]>> wrote:
FYI, there's an RFC explaining all this already: 3819

Joe

On 1/16/2015 12:04 PM, Templin, Fred L wrote:
> +1
>
>> -----Original Message-----
>> From: Int-area 
>> [mailto:[email protected]<mailto:[email protected]>] On 
>> Behalf Of Brian E Carpenter
>> Sent: Friday, January 16, 2015 11:16 AM
>> To: Alexandru Petrescu; [email protected]<mailto:[email protected]>
>> Subject: Re: [Int-area] About draft-baccelli-manet-multihop-communication-04
>>
>> Alex,
>>
>>> but to improve the layers below IP such as to have IP run unmodified.
>>
>> In the general case that is impossible, because the SDO that develops
>> the lower layer isn't interested. If the lower layer is intrinsically
>> NBMA then for sure ARP or ND+DAD will not work as designed. If the lower
>> layer doesn't support a physical MTU of at least 1280 IPv6 will not work
>> as designed. So in the general case both an adaptation layer and an
>> NBMA solution are required. And as you know, there are other "Ethernet"
>> assumptions that don't apply in a low-power wireless scenario.
>>
>> Of course the goal is "IP over Everything" but that isn't the same as
>> "Everything must be like Ethernet", which you seem to imply.
>>
>> In fact when you read draft-baccelli-manet-multihop-communication
>> (and imagine what its security section will say when it's been
>> written), I think the conclusion is that a great many things have
>> to change, not in the IP packet format, but in the ecosystem
>> currently provided by ARP/DHCP or RA/ND/DAD/SLAAC/DHCPv6.
>>
>>   Brian
>>
>> _______________________________________________
>> Int-area mailing list
>> [email protected]<mailto:[email protected]>
>> https://www.ietf.org/mailman/listinfo/int-area
>
> _______________________________________________
> Int-area mailing list
> [email protected]<mailto:[email protected]>
> https://www.ietf.org/mailman/listinfo/int-area
>

_______________________________________________
Int-area mailing list
[email protected]<mailto:[email protected]>
https://www.ietf.org/mailman/listinfo/int-area

_______________________________________________
Int-area mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/int-area

Reply via email to