Subject: Duplicate Address Detection

From: "Nils Agne Nordbotten" <[email-masked]>
Date: Fri, 28 Jun 2002 13:40:52 +0200

Hello,

RFC 2462 (IPv6 Stateless Address Autoconfiguration) states that:
"....for a set of addresses formed from the same interface identifier, it is
sufficient to check that the link-local address generated from the
identifier is unique on the link. In such cases, the link-local address MUST
be tested for uniqueness, and if no duplicate address is detected, an
implementation MAY choose to skip Duplicate Address Detection for additional
addresses derived from the same interface identifier..."

It also says: ".....To accommodate sites that believe the overhead of
performing Duplicate Address Detection outweighs its benefits, the use of
Duplicate Address Detection can be disabled through the administrative
setting of a per-interface configuration flag....."

Does this last segment mean that Duplicate Address Detection can be skipped
completely at a site, or does it refer to the MAY part of the first segment
(that it may be skipped for additional addresses, but not for the link-local
IPv6 address)?

I belive skipping this check completely could be effective in networks with
low resources and where each device has a unique interface identifier.

Thanks in advance.

Nils Nordbotten

--------------------------------------------------------------------
IETF IPng Working Group Mailing List
IPng Home Page:                      http://playground.sun.com/ipng
FTP archive:                      ftp://playground.sun.com/pub/ipng
Direct all administrative requests to [email-masked]
--------------------------------------------------------------------

---

From: Francis Dupont <[email-masked]>
Date: Fri, 28 Jun 2002 15:04:25 +0200

In your previous mail you wrote:

   
=> this (the fact RFC 2462 and the address architecture I-D don't make
a clear choice between DAD and DIIDD (Duplicate Interface ID Detection))
is already well known but not (yet?) fixed.

=> I count this as a vote in favor of DIIDD.

Regards

[email-masked]

PS: BTW I haven't seen yet the call for agenda for the IPv6 WG...