Re: I-D Action: draft-ietf-6man-resilient-rs-02.txt

[Erik Nordmark <[e-mail]>]

On 1/29/14 11:34 AM, Erik Kline wrote:
>> A host on a multicast-capable link on which "unsolicited multicast Router Advertisements are never sent" will have to use the same transmission behavior as a host on a non-multicast-capable link, so that the host can learn of changes in the link prefixes in a timely fashion.
> Not necessarily.
>
> Consider the situation in a which a router responds to multicast RSs
> with unicast RAs.  The host may in fact continue to receive unicast
> RAs periodically.
Erik,

In such an approach when would the router stop unicasting RAs to a 
particular address? Forever? Until NUD fails? What is the host was gone 
for 30 seconds without the host noticing and as a result the router saw 
a NUD failure.

Without clear details one can't say 1) whether this will work and 2) 
weather it would save any resources.

Note (in case it isn't obvious) that a router can respond to a RS with a 
unicast RA - that is already allowed by 4861 and its predecessors.

    Erik