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

[Alexandre Petrescu <[e-mail]>]

Le 10/04/2019 à 11:04, Ole Troan a écrit :
>>>>> "At least" does not mean "the value should be at least 10" in that phrase.
>>>>>
>>>>> Do you think we should say otherwise?
>>>>
>>>> To me there is nothing in the actual text to tell me that "at least"
>>>> qualifies the "/10". I think you could rephrase as
>>>> "This subnet's prefix MUST lie within the link-local prefix fe80::/10 ..."
>>>>
>>>> However, see Jinmei's messages about conformance with RFC 4291.
>>>>
>>>> I think there might be unexpected side effects from using an
>>>> address like fe80:1::1. What if some code uses matching with
>>>> fe80::/64 to test if an address is link-local? I agree that
>>>> would be faulty code, but you would be the first to discover it.
>>> Indeed.
>>> If you absoultely must cut and paste text from 2464:
>>
>> YEs, that is how we started.  We cut and paste from 2464.
>>
>>> 5.  Link-Local Addresses
>>>     The IPv6 link-local address [AARCH] for an Ethernet interface is
>>>     formed by appending the Interface Identifier, as defined above, to
>>>     the prefix FE80::/64.
>>>         10 bits            54 bits                  64 bits
>>>       +----------+-----------------------+----------------------------+
>>>       |1111111010|         (zeros)       |    Interface Identifier    |
>>>       +----------+-----------------------+----------------------------+
 >>>
>>> I presume there is support for bridging 802.11p and other 802.3 links?

In the IP-OBUs that I know there is IP forwarding between 802.11-OCB 
(earlier 802.11p) and 802.3, not bridging.

In some IP-OBU (Internet Protocol On-Board Unit) some non-OCB interfaces 
are indeed bridged.  E.g. the Ethernet interface is bridged to the WiFi 
interface; that helps with DHCP, tcpdump and others to see one a single 
- bridged - interface.

Bridging may be, but it is not a MUST.  There is no necessarily any 
bridging between the 802.11-OCB interface and other interface, neither 
bridging between the multiple 802.11-OCB interfaces that might be 
present in the same computer.

Do you assume bridging of 802.11-OCB interface to Ethernet interface is 
always there?

Note: I also heard many comments suggesting that EAL is akin to 
'bridging'.  I do not know whether you refer to that perspective.  If 
yes, we can discuss it separately.

Alex

[...]

>>> And that the MAC address length of this link type is also 48 bits?
>>
>> YEs, the length of MAC address on 802.11 mode OCB is also 48.
>>
>>> If the two assumptions above hold, then I see zero justification for pushing the 64 bit boundary in this draft.
>>
>> Let me try  to understand the first assumption.
> 
> 
> Ole
>