Alper, Simply because of address spoof DOS we must at least permit DAD. The cost is only at node-on. Now the timers and lifetimes administration for a mobile network could be a problem but that is tunable. I believe we are talking miliseconds. What we need are some tests. I will ask our folks to test our handhelds for DAD timings.
But any implementation can turn anything it wants off for v6. We can say MUST or SHOULD but users may or may not use it. I am not comfortable changing DAD for anything here quite yet based on the arguments on the "for" side at all. /jim -----Original Message----- From: Alper E. YEGIN [mailto:[EMAIL PROTECTED]] Sent: Tuesday, October 15, 2002 5:12 PM To: [EMAIL PROTECTED]; 'Pekka Savola' Cc: 'Nick 'Sharkey' Moore'; [EMAIL PROTECTED] Subject: Re: Optimistic DAD draft ... Hi Tony, > True, but the term 'hand-off' implies a make-before-break process, > else the MN is just establishing itself on a new link. Given it has > the opportunity to be aware of multiple links, it can decide when to > switch. I am arguing that it complete DAD 'before' it makes that > decision, not after. I don't think we can consider all "handoffs" as 'make-before-break'. There exists some link-layer technologies that allow this, but not all have such capability. Completing DAD before handover requires either movement anticipation or make-before-break, both of which are not widely applicable. Therefore solving DAD latency for general case is a valid approach, imo. alper > > Tony > > > -----Original Message----- > > From: Pekka Savola [mailto:[EMAIL PROTECTED]] > > Sent: Tuesday, October 15, 2002 1:32 PM > > To: Tony Hain > > Cc: 'Nick 'Sharkey' Moore'; [EMAIL PROTECTED] > > Subject: RE: Optimistic DAD draft ... > > > > > > On Tue, 15 Oct 2002, Tony Hain wrote: > > > [...] it would seem the prudent thing for a MN to do is > > establish DAD > > > for all candidate prefixes well before it is ready to start using > > > them. [...] > > > > Isn't there a problem with how this could be done, as > > currently specified? > > > > One can't perform DAD before being on the link. > > > > > > -----Original Message----- > > > > From: [EMAIL PROTECTED] > > > > [mailto:[EMAIL PROTECTED]] On Behalf Of Nick > > > > 'Sharkey' Moore > > > > Sent: Monday, October 14, 2002 7:58 PM > > > > To: [EMAIL PROTECTED] > > > > Subject: Optimistic DAD draft ... > > > > > > > > > > > > G'day IPng-ers, > > > > > > > > One of the big issues in getting low-latency > > > > handovers working for IPv6 mobility is the long delay involved > > > > in > > > > completing DAD. > > > > > > > > One option is to allow the Mobile Node to communicate while the > > > > address is still Tentative (optimistically assuming that DAD > > > > will succeed), but to adjust its ND / SAA behaviour in order to > > > > minimize disruption in case of an address conflict (and maintain > > > > correct interoperation with > > unmodified nodes). > > > > > > > > We've kicked the idea around a little on mobile-ip, > > > > and I've formalized my thoughts into an internet draft, > > which should > > > > get published soon. In the meantime, you can find it at > > > > <http://www.ctie.monash.edu.au/ipv6/fastho.htm> > > > > (tentatively titled draft-moore-ipv6-optimistic-dad-00). > > > > > > > > I'd be interested in your opinions on the draft, and its > > > > potential suitability for standards track. > > > > > > > > > > > > cheers, > > > > Nick > > > > -- > > > > Nick 'Sharkey' Moore <[EMAIL PROTECTED]> > > > > Research Fellow, CTIE Tel: +61 3 9905 3707 > > > > Monash University, Australia Fax: +61 3 9905 5358 > > > > > > -------------------------------------------------------------------- > > > > 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] > > > > > > -------------------------------------------------------------------- > > > > > > > > > > > > > ------------------------------------------------------------------ > > > -- > > > 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] > > > -------------------------------------------------------------------- > > > > > > > -- > > Pekka Savola "Tell me of difficulties surmounted, > > Netcore Oy not those you stumble over and fall" > > Systems. Networks. Security. -- Robert Jordan: A Crown of Swords > > > > > -------------------------------------------------------------------- > 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] > -------------------------------------------------------------------- > -------------------------------------------------------------------- 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] -------------------------------------------------------------------- -------------------------------------------------------------------- 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] --------------------------------------------------------------------
