Hi, The IPv6 standards allow nodes to autoconfigure their host ID's and EUI-64 is one standard way to do that. However, autoconfiguration is not mandatory and neither is using EUI-64 for it. Accordingly, even if MAC addresses were guaranteed to be unique, DAD is required for ensuring uniqueness.
Autoconfiguration could be done through EUI-64 but also through DHCP or through the randomized procedure specified by RFC3401. Other ways of configuring interface addresses include CGA (Cryptographically Generated Addresses) and the good old manual configuration. Regards, Salah -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of shariq haseeb Sent: Wednesday, July 04, 2007 5:04 AM To: [EMAIL PROTECTED]; [email protected] Subject: Re: [mipl] Some General Question Hi! Here is what I think. Yes, it is true that if the manufacturer has not made mistakes, the MAC address is unique. However, lets consider the following scenario. Coincidently, a user on the foreign network has manually configured an address that happens to be the address which you are suppose to configure when you reach the foreign network. In that scenario, you have a conflict. The odds of having a conflict are minimal. If i am not mistaken, an authority in MIPv6 mentioned that the odds are 1 in a billion. However, if intentionally done to harm someone, the odds might become great :). In another scenario, lets say you have registered your address with your home agent, then suddenly there is a power failure on your machine or something. Your machine gets terminated abruptly therefore, the binding is still present in the home agent. When your machine comes up and it tries to register the same address which it had before, then there is a conflict. On the same note, MIPL does allow optimistic handoff, where there is no need to perform DAD. rgds, Shariq --- [EMAIL PROTECTED] wrote: > > Hello > > I have got some basic questions regarding the need > to perform DAD and a confirmation would be > appreciated > > Obviously DAD is performed to check the uniqueness > of the auto-configured data, but since the > auto-configured address is formed by appending the > prefix advertised by RA with the MAC address of the > interface, and since MAC addresses are globally > unique then why perfom DAD? > > For example when a MN moves to a visit net, then if > for example if the MAC address is AA:BB:CC:DD:EE:FF > and the advertised prefix was 2001:001b::1/64 then > the newly autoconfigured address would be > 2001:001b:0:1:AABB:CCFF:FEDD:EEFF. > Am I correct? If i am then under what circumstances > can this address have a conflict with any other node > on the new link as the MAC address is globally > unique??? > > A reply is eagerly awaited > > ZFaqeer > > > > > _________________________________________________________________ > Local listings, incredible imagery, and driving > directions - all in one place! Find it! > http://maps.live.com/?wip=69&FORM=MGAC01 > _______________________________________________ > mipl mailing list > [email protected] > http://www.mobile-ipv6.org/cgi-bin/mailman/listinfo/mipl > ________________________________________________________________________ ____________ Get the free Yahoo! toolbar and rest assured with the added security of spyware protection. http://new.toolbar.yahoo.com/toolbar/features/norton/index.php _______________________________________________ mipl mailing list [email protected] http://www.mobile-ipv6.org/cgi-bin/mailman/listinfo/mipl _______________________________________________ mipl mailing list [email protected] http://www.mobile-ipv6.org/cgi-bin/mailman/listinfo/mipl
