On Fri, Oct 18, 2002 at 01:18:57PM -0400, Vladislav Yasevich wrote:
> 
>   - Sections 2.1 and 2.2 are not very clear.  For example, in
> section 2.2 there are two bullets that modify section 5.4.3,
> but these 2 bullets are very ambigiouse as to what parts of
> [rfc2462 sec. 5.4.3] they apply to.  It would be better if
> the draft spelled out the particular modified behavior.

Okay, I'll look into making this less ambiguous. The difficulty is
that the changes are relatively small compared to the main text
(eg, 2461/2462), and so I've tried to emphasize the changes rather
than providing the full rules and making people work out the 
difference!

>     Where are these link-layer addresses taken from?
>     The router will ignore both NS and NA for the following reasons:
>      - NS is send  without the Source Link-Layer Address option.
>      - NA is sent with the O-bit = 0.

Well, more to the point, S=0. So if it doesn't have an entry, it will
most likely ignore it.

Hesham points out that this is probably an assumption of Fast Handovers
type behaviour on my part: guilty as charged. There's nothing more
effective than peer review to find your assumptions!

In the Fast Handovers case, the router probably has some traffic waiting
for the MN. I'll consider more carefully what will happen if this is
not the case and post again on Monday.

>     The only place so far the node can get the address of the router is from
>     the RA, but Source Link-Layer Address option is optional in RAs
>     (it's a MAY in 2462).

Ummm. Interesting. 2461 says "A router MAY omit this option in
order to enable inbound load sharing across multiple link-layer
addresses.", but I'll admit I'd never considered it!

>    For the simple case, there is a very minor effect on the operation
>    of non-optimistic nodes.  An optimistic node will force the state
>    of all REACHABLE entries to transition to STALE and may force NUD.
>    This is a very minor effect, but it should be noted.

A NA with S=0,O=0 for a REACHABLE entry will have no effect on the
entry according to the Appendix C state machine, and these are the
only NAs which the ON will sent to All Nodes which Tentative. 
Admittedly an NA with S=1,O=0 will reset a REACHABLE entry to STALE,
but why is the correspondent soliciting for a REACHABLE entry?
(Or have I missed something elsewhere?)

>    Also, the initial delay of the first NUD probe is 5 seconds which is
>    rather substantial amount of time that the packets may be blackholed
>    in the case of proxy NAs.

Yep. That's probably the worst outcome on the list, but I think
it is acceptable as it is both unlikely (new connection on colliding
address) and recoverable (by NUD). 

Thanks for your feedback ... you've certainly given me lots to 
think about on Monday!

-----Nick
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