Re: [ipwave] link-local text (Re: [Int-dir] Intdir early review of draft-ietf-ipwave-ipv6-over-80211ocb-34)

[Alexandre Petrescu <[e-mail]>]

for this particular detail,

Le 12/04/2019 à 20:36, 神明達哉 a écrit :
[...]
>  If so, it's better to say so explicitly, e.g:
> 
>     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
>     MUST be a single-like subnet.  It means that all nodes in the
>     subnet must be able to communicate directly using their link-local
>     unicast addresses.

I added the last phrase (all nodes in the subnet must be able to 
communicate directly using their lls).

Remark that, for me, that is a phrase with some risks of ambiguity. 
'Communicate directly' may mean to you that it does not go through IP 
Router, but to others may mean it does not go through Access Point. 
This 'communicate directly' means many things to many people.

For best use, at this time I think this 'communicate directly' should be 
qualified by the layer (i.e. at network layer).

Also, 'using their link local unicast addresses' can mean to some that 
there exist link local multicast addresses (they dont, as proven by a 
search of "link-local multicast address" in RFC4291; at most maybe some 
groups with ll scope exist); also it does not say where these ll 
addresses sit: if they are in the src and dst fields then you are right, 
but if they are in some inner header, encapsulated, then it's ambiguous.

Alex

> 
> If there's no such special intention, I'd suggest just removing the
> second sentence (with moving the requirement of having a LL address to
> Section 4.3).
> 
> --
> JINMEI, Tatuya