Hi Jonathan: I tend to favor the FFFE because it's a space where other mechanisms will not play. For instance, I do not expect any manual configuration to place an FFFE in the middle of the IID knowing that it's supposed to be used for EUI padding. If the subnet spans farther than the LoWPAN, I can imagine a manual configuration on a server or a router somewhere that could use an address that matches a ::1:xxxx'.
Cheers, Pascal > -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Jonathan Hui > Sent: Wednesday, March 31, 2010 5:02 AM > To: Samita Chakrabarti > Cc: [email protected]; [email protected]; Erik Nordmark > Subject: Re: [6lowpan] #65: Deriving IIDs from Short Addresses > > > Hi Samita, > > On Mar 30, 2010, at 7:43 PM, Samita Chakrabarti wrote: > > > I would vote for option 1. [ existing definition in rfc4944 -] > > Just to be clear, option 1 still requires an update to RFC 4944 to > specify that the PAN ID is no longer used in constructing the IID. > Minimally, 6lowpan-hc either needs to (i) update Section 6 of RFC 4944 or (ii) > no longer point to RFC 4944 and specify how to reconstruct the IID from a > short address. I am fine with either, but if we go with the latter, then the > 6lowpan-nd document needs to update Section 6 of RFC 4944. > > > 1) Maintain the RFC 4944 translation (short address -> ethernet > > address -> > >> 64-bit IID). Generated IIDs will be 64 bits in length and of the > >> form (0000:00ff:fe00:xxxx), where xxxx is the short address. > > > > This is simple and easy to understand and compute. ND assumtion is > > that there is one single prefix per 6LoWPAN. If you are talking about > > PANs under a 6LowPAN, then I think it is too implementation specific > > and we don't need to standardize it at this point. > > Yes, I agree with the desire of maintaining 64-bit prefixes. > > > So for simplicity and not adding more complexity to ND > > autoconfiguration, can we say that > > 6LoWPAN-unique-prefix::00ff:fe00:xxxx would be the IPv6-address > > derived from short address with the above 64-bit IID? > > I think the only argument now is whether the 64-bit IID should take the form > '::ff:fe00:xxxx' or simply '::1:xxxx'. The latter is easier to type IMHO, but I > agree it is a minor point. Either way, we require an update to RFC 4944 and > 6lowpan-hc. > > -- > Jonathan Hui > > _______________________________________________ > 6lowpan mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
