Re: [Autoconf] Updated ad hoc addressing model document

["Teco Boot" <[e-mail]>]

Hi Thomas,

>-----Oorspronkelijk bericht-----
>Van: Thomas Heide Clausen [mailto:[e-mail]]
>Verzonden: donderdag 4 februari 2010 13:43
>Aan: Teco Boot
>CC: 'Charles E. Perkins'; [e-mail]
>Onderwerp: Re: [Autoconf] Updated ad hoc addressing model document
>
>
>On Jan 30, 2010, at 12:22 PM, Teco Boot wrote:
>
>> Charlie,
>>
>>>>>> My requirement is that L3 communication between nodes, that have
>>>>>> L2
>>>>>> connectivity, must be possible in all conditions, including
>>> conditions
>>>>>> with a non-operational MANET protocol.
>>>>>>
>>>>>>
>>>>> I don't see that the addressing model prevents any such L3
>>>>> communication.
>>>>>
>>>> How are packets forwarded?
>>>> The destination address (which is direct L2 neighbor in this case)
>>>> needs to be found in a forwarding table, normally the routing table.
>>>> Neighbor cache could be used also.
>>>> How to get this info in such a table?
>>>>
>>>
>>> Node A broadcasts a "Hello" message.
>>> Node B hears it, and puts node A in its forwarding table.
>>>
>>> The nodes may take subsequent actions to verify
>>> bidirectionality, exchange other table entries, etc.
>>
>> My point is that L3 communication becomes dependent on a L3 routing
>> protocol. We didn't have this in the IP stack before.
>
>Well.....L3 communication depends on a populated routing table, thus
>on something populating the routing table.
>L3 multi-hop communications depends on something clever (a routing
>protocol, a DHCP server, a human, for example and depending on the
>place) populating routing tables.
>
>I do not see what this document does that changes that?

Up to now, all IP addressing models I am aware of provide 1-hop L3
communication between nodes that have L2 connectivity.

The proposed addressing model for MANETs breaks this. Now there
is a need for something clever. This clever thing could be
stopped. 


>>> One should think of updating the IPv6 RFCs, since the link-local
>>> constructions contained therein were written _explicitly_ in
>>> disregard of the needs for wireless links of the sort familiar to
>>> practitioners in this group.
>>
>> I use link-locals on wireless links, and it works great.
>> What is your point?
>
>I am not Charlie, so I won't speak to what his point is.....but a
>point can be made that you have observed a particular and specific
>setup in which this holds true. That's good!
>
>This document aims at describing something that can hold in more than
>one particular  and specific setup and, if respected, will allow
>unencumbered operation, outside of a particular and specific setup.

There is no reason not using link-locals for 1-hop traffic.
If you say this is a particular and specific setup, is this a 
qualification for IPv6?
If not, what are you referring to?


Regards, Teco.