Re: [Int-dir] Intdir early review of draft-ietf-ipwave-ipv6-over-80211ocb-34 - 'conforming IPv6' - fe80::/10 vs fe80::/64

[Ole Troan <[e-mail]>]

Alexandre,

>>> You said: if OCB is still 48bit, and if there is bridging
>>> OCB-Ethernet, then no reason to be different than rfc2464.
>>> I said: OCB is still 48bit, but there is no bridging OCB-Ethernet.
>>> The conclusion is: there is reason to be different from RFC 2464.
>> Why?
>>> Now, you give a different conclusion.
>>> Excuse me, I would like to clarify this please?
>> Clarify what?
> 
> You said if OCB-Ethernet bridging then no need of update.  Then you
> concluded differently.  That needs clarification.

No need to update 4291.

>> That a link-layer that looks an awfully lot like Ethernet
> 
> It looks an awful lot like Ethernet, but it can not be bridged to it. The 'brctl' and 'brconf' software issue errors when trying to link OCB interface to Ethernet interface.
> 
>> [That a link-layer that looks an awfully lot like Ethernet] should not
>> follow the 64-bit boundary and the definition of the link-local
>> address mapping of rfc2464? Section 4.5.1 is already clear on that.
> 
> If OCB can not be bridged to Ethernet then OCB interfaces are free to have a 65bit IID, without fearing lack of interoperability to an Ethernet interface with 64bit IID.  The IP forwarding does not care about IID length, and there is no bridging.

Rathole.

>> I think the only thing we are asking you is to change the following
>> paragraph:
>> OLD: A subnet is formed by the external 802.11-OCB interfaces of
>> vehicles that are in close range (not by their in-vehicle
>> interfaces).  This subnet MUST use at least the link-local prefix
>> fe80::/10 and the interfaces MUST be assigned IPv6 addresses of type
>> link-local.
>> NEW: A subnet is formed by the external 802.11-OCB interfaces of
>> vehicles that are in close range (not by their in-vehicle
>> interfaces). A node MUST form a link-local address on this link.
> 
> Makes sense, I will add it.
> 
> Then somebody will ask what is the prefix length of the LL prefix on OCB?  What reference should I give to the person asking?
> 
> The reference is RFC2464 that says 64bit IID.  But that is for Ethernet and EThernet can not be bridged to OCB.
> 
>> Not quite sure what value that paragraph adds in the first place. You
>> could probable remove it.
> 
> The value in mentioning /10 is that it works on OCB (it works also on Ethernet but not on all OSs, and so  it may risk violating a section).

Because some implementations can handle it, is not a reason to diverge from RFC2464.
Stick with the RFC2464 definition.

Remove the paragraph and just reference 2464, and you should be fine (at least from the link-local perspective) in this draft.

Anyone else see a problem with that solution?

Cheers,
Ole