Subject: RE: [mobile-ip] newest text for MIPv6 movement detection

From: "Karim El-Malki (EAB)" <[email-masked]>
Date: Mon, 12 May 2003 18:09:49 +0200

It seems to limit the gain of using L2 indications.
If you consider the case where you have actually moved subnet, you need
to send a NS and wait for several seconds before trying to discover the
new default router. This is slower than if we discarded L2 indications
completely and waited for an RA. I would prefer keeping the L2 indications
text since it is useful but also allowing the MN to send a RS immediately
to check whether it has moved. Is it a big problem given that we already
rate limit responses?

/Karim

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From: "Ed Remmell" <[email-masked]>
Date: Mon, 12 May 2003 10:40:09 -0700

Karim -

> to check whether it has moved. Is it a big problem given that we already

Erik's wording had no real requirements, it is a suggested implementation.
Earlier in this section, it states that this is a generic non-optimized
algorithm, and that we expect that better/faster movement detection
algorithms will be proposed and adopted later. This is more to give
implementors guidance. The method you refer to I believe has been called
"eager cell switching" on this list recently (or is related) - there are
complexities involved with doing that in an optimal manner, for example
consider the case where there are two or more routers on the link or the MN
can hear multiple routers simultaneously (note that hearing a router's RAs
isn't the same as bi-directional reachability confirmation). That's why
elsewhere in this section there is the recommendation that if you've already
discovered a perfectly good bi-directionally reachable router, you should
generally continue to try using it as your default router even when you
receive a RA from a new/different router.

So, this text does not specifically allow or prohibit any MN behavior, it
isn't requirements text it is more informational in purpose. We were just
trying to show how L2 indications fits with a probing mechanism.

Thanks.
- Ed