Subject: [DNA] optimistic DAD: sending router solicitations

From: [email-masked]
Date: Fri, 24 Jun 2005 12:43:09 -0700

Hi,
  I am studying optimistic DAD and had the following questions.

Without optimistic DAD, when DAD completes, the address is configured on the interface and the node starts sending router solicitations. But with Optimistic DAD, the draft suggests that router solicitations MAY be sent from an optimistic address without including the SLLAO option. When optimistic DAD completes, (i) do we have to configure the address on the interface again, (ii) do we stop the router solicitations that were scheduled when optimistic DAD started, and (iii) when we start sending router solicitations (afte Optimistic DAD completes), do we allow a delay or send it right away.

Thanks
Mahesh

---

From: James Kempf <[email-masked]>
Date: Fri, 24 Jun 2005 17:12:23 -0700

I think the basic idea is that the host changes the addresses to Optimistic
prior to sending the RS after it has detected a link event indicating a link
move, and includes TSLLAO in the RS (the latter is already in the draft) so
the router can unicast the RA back but the router's neighbor cache doesn't
get changed. The host also deferrs oDAD signaling (NA) until after the RA
returns. If the RA comes back and the host hasn't changed IP links, it can
switch the addressses back to Confirmed. If the RA comes back and the host
has changed IP links, the host moves the addresses to Deprecated and
configures new addresses on the link as Optimistic and does the oDAD
signaling (NA).

So the idea is to couple DNA with oDAD in a way that reduces the amount of
signaling and allows the host to recover quickly if it hasn't changed IP
links.

            jak

----- Original Message ----- 
From: <[email-masked]>
To: <[email-masked]>
Sent: Friday, June 24, 2005 12:43 PM
Subject: [DNA] optimistic DAD: sending router solicitations

> Without optimistic DAD, when DAD completes, the address is configured on
the interface and the node starts sending router solicitations. But with
Optimistic DAD, the draft suggests that router solicitations MAY be sent
from an optimistic address without including the SLLAO option. When
optimistic DAD completes, (i) do we have to configure the address on the
interface again, (ii) do we stop the router solicitations that were
scheduled when optimistic DAD started, and (iii) when we start sending
router solicitations (afte Optimistic DAD completes), do we allow a delay or
send it right away.