> X-Authentication-Warning: sunroof.eng.sun.com: majordomo set sender to >[EMAIL PROTECTED] using -f > From: Robert Elz <[EMAIL PROTECTED]>
> One obvious one is when I have two links, and have assigned pfx1::1 to > my favourite node on one of them, and pfx2::1 to my favourite (different) > node on the other, and then I decide to merge the links into one. Applying > both prefixes to the link is easy, so I shouldn't have to renumber anything > just because of this (pyhsical) change (maybe a temporary one caused by > the death of a switch, while waiting upon a replacement - assuming I'm > too cheap to buy switches that support vlans...). But now I have two ::1's > on the one link. But, even with DAD, you will have problems. You are announcing pfx1 and pfx2 on the same link. Thus, because both nodes have id=1 - both nodes will try to configure now pfx1::1 *AND* pfx2::1 and collide each other. - both nodes can now validly try to configure fe80::1, and collide on that - if a new pfx3 is announced, both nodes will collide on "pfx3::1" I'm not saying above is bad situation. It does require implementation to keep track of each combination, to remember wich prefix/id combinations have collided (or it has to keep a separate list of collided addresses, so that it doesn't try to reuse those combinations later). With DIID, you can remove the collided ID, and it will not be used. Of course, implementations can be more complicated: at least I have possibility to use "atomic" address, which will allow me to use "pfx1::1", even if id=1 is removed. You configure prefix, id or atomic address. -------------------------------------------------------------------- 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 PROTECTED] --------------------------------------------------------------------
