I agree with Zach. IP over foo has been taken up by IETF for all sorts of "foo"s and 6lowpan ND is just doing that.
Regards, Behcet ----- Original Message ---- > From: Zach Shelby <[email protected]> > To: Mathilde Durvy <[email protected]> > Cc: [email protected]; [email protected]; [email protected] > Sent: Wed, May 5, 2010 10:42:14 AM > Subject: Re: [6lowpan] [Roll] how does a node get an IP address > > Hi, On May 5, 2010, at 17:18 , Mathilde Durvy (mdurvy) wrote: > > Hi Pascal, > > I fully agree with you. > In my opinion > anything spanning multiple IP hops should not be done by ND. That logic > doesn't work anymore with route-over LoWPANs. As the prefixes are spanning > the > whole LoWPAN there is a natural need for ND to help with that. In the case of > RPL, the WG may decide to disseminate some things such as prefix information > between routers in a LoWPAN using the routing protocol. 6lowpan-nd-09 states > clearly that you may do that, so nothing stopping RPL there. What is this > argument about? You are complaining about something that is not a problem? > Now RPL isn't the only routing protocol.... 6lowpan-nd-09 provides an > optional mechanism of using RS/RA for disseminating prefix and context > information between all routers in a LoWPAN that is routing protocol > independent. Regardless of RPL, this will surely come in handy and some > routing > protocols may even specify to use this mechanism. Let me remind > you of how RPL started by the way. In the beginning the idea was to piggyback > RPL information on ND traffic as there were already similar flows. Eventually > the WG decided to give RPL its own messages instead of piggybacking as ND > options. Now it has gone to the extreme of RPL being the one and only > protocol > and everything must be carried on that.... Quite a change! Next we could > piggyback DHCPv6 on RPL, use RPL for DAD, and what the heck, let's go for DNS > too... Starts to sound like a shopping-TV ad for a > super-vegetable-processing-miracle doesn't it? > > On a > related topic.... > 6lowpan network have the particularity that you cannot > use on-link prefix > due to the non-transitivity of the wireless links. > This means we need to > tell routers how to reach neighboring IPv6 hosts. > So essentially 6lowpan-ND > is using a registration mechanism to establish > a "route" between the router > and the host. It is actually > letting the host and router know about each other (router discovery), their > reachability (NUD) and their L2 addresses (address resolution). These are all > standard features of ND. > It is not clear to me whether this is the > role of ND or of the routing > protocol. I think it could actually be > both. > Hence the questions: > - Are IPv6 hosts possible in a > 6lowpan network where the RPL protocol is > used? Better be, or you > just broke an important model of IPv6. I would say it MUST be possible for > hosts > to attach to a LoWPAN running RPL (and stay blissfully ignorant of RPL). > > - Should IPv6 hosts be part of a RPL topology (as leaf node) or > should IPv6 > hosts use the 6lowpan-ND host-router spec? ND is > clearly the standard host-router interface regardless of IPv6 or 6LoWPAN. > Forcing hosts to know anything about RPL would be insane... > Zach > > Best, > Mathilde > > > -----Original Message----- > From: > ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected] [mailto:> > ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected]] On Behalf > Of > Pascal Thubert (pthubert) > Sent: jeudi, 29. avril 2010 > 09:01 > To: > href="mailto:[email protected]";>[email protected]; > Richard > Kelsey > Cc: > href="mailto:[email protected]";>[email protected]; > > ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected] > Subject: Re: [Roll] > how does a node get an IP address > > Hi Zach: > > I > have yet to review the new ND-09 but my guts tell me that it is the > wrong > place to do the job. Router to router is usually routing protocol > land and > ND is definitely not a routing protocol. > > The > main question is how long can a router advertise a prefix, and the > > answer is, as long as it is in the same subnet of an authoritative > router > that owns the prefix. > Asserting the continuous > reachability of the authoritative router is a > routing protocol problem. > Maintaining a subnet together is the job for a new > form of Gateway > Protocol, a Subnet Gateway Protocol RPL is just that. > > Let > see: > > - Propagating the RA content is not an ND intrinsic > problem, it only comes > with route over. And route over comes with a > routing protocol. > - the route over protocol should be able to tie the > route over subnetwork > together so it is a SGP. > > So why > can't we just say in 6LoWPAN ND that you for those who use it in > route > over we expect an SGP to tie the route over subnetwork together and > that > the SGP should transport the RA content, maintaining the validity with > > the reachability of the authoritative router? I can write that text if > you > wish. > > It seems that we have a reasonable consensus > in this thread to do exactly > that in RPL anyway... > > > Pascal > >> -----Original Message----- >> From: > ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected] [mailto:> > ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected]] On Behalf > > Of >> > href="mailto:[email protected]";>[email protected] >> > Sent: Tuesday, April 27, 2010 10:36 PM >> To: Richard > Kelsey >> Cc: > href="mailto:[email protected]";>[email protected] >> Subject: Re: [Roll] > how does a node get an IP address >> >> Hi > Everyone, >> >> Let me jump into this thread - just to make > things more interesting > ;-) First, I >> recommend everyone goes > and reads 6lowpan-nd-09 which was submitted >> today. When it comes to > ND, you need to separate two interfaces. >> >> 1. The > host-router interface >> >> Hosts know absolutely nothing > about RPL (nor should they). Thus in > this case >> ND* does the > job, and RS/RA is used for obtaining a prefix and > initializing > its >> addresses. I think some people in the thread are referring to > this. >> >> 2. The router-router interface >> > >> As in RFC4861, in 6lowpan-nd-09 routers have more flexibility > than > hosts in >> how they obtain prefix information (among > other things). nd-09 does > include >> an optional technique for > an authorative border router to disseminate > PIOs >> and CIOs > (Context Information Options) between the border router and > > all >> routers in the LoWPAN using RAs. It is actually a decent > mechanism and >> improved over early versions. The draft clearly > states that it is > optional as a >> routing algorithm may > already do this. So Pascal is correct in that > respect. I >> > haven't followed the thread well enough to have an opinion if RPL > should > do >> that. >> >> Routers will also find other > features of 6lowpan-nd-09 useful, for > example >> during initial > bootstrapping, to maintain their default router and > neighbor >> > caches, avoid the need for address resolution, and to perform NUD. The > >> draft (tries to) clearly state when features are required or > optional > for a >> router. >> >> > Zach >> >> >>>> From: Michael Richardson > <> href="mailto:[email protected]";>[email protected]> >>>> > Date: Tue, 27 Apr 2010 10:38:47 -0400 >>>> > >>>>>>>>> "Richard" == Richard Kelsey <> >>>>>>>>> ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected]> > > writes: >>>>>> Date: Tue, 27 Apr 2010 14:18:32 +0200 From: > "Pascal Thubert >>>>>> (pthubert)" <> ymailto="mailto:[email protected]"; > href="mailto:[email protected]";>[email protected]> >>>>>> > >>>>>> The question here is that the authoritative routers > need to >>>>>> disseminate the PIO (and the RIO) to all > routers in the > subnet. >>>> >>>> > Richard> How do other routing protocols (OSPF, IS-IS, AODV, > > OLSR) >>>> >>>> I can only speak for OSPF and > ISIS. >>>> Neither deal with multi-hop subnets or with any kind > of address >>>> assignment. >>> >>> Why > should RPL be any different? Yes, it will be run on multi-hop > >>> subnets, but I still do not see how this affects the > routing. >>> >>>> Both were written when multicast > was very new. >>> >>> I am not sure how RPL's handling > of multicast matters here. >>> While RPL is required to route > multi-hop multicasts, ND uses >>> link-local multicasts, which do > not require routing. >>> >>>> Richard> I > understand that multi-hop subnets are a problem for ND, >>>> > Richard> but I don't see how the routing protocol is > affected. >>>> >>>> RPL either requires 6lowpan, > or it doesn't. >>> >>> RPL should work fine with > ordinary ND. Why would it require > 6lowpan? >>> > >>>> If it doesn't, then it has to provide for ND to work, or > for > another >>>> protocol to replace it. >>> > >>> ND works fine, using link-local, one-hop multicasts. RPL > need not > be >>> involved. >>> >>> > If someone wants to run RPL on a node that uses neither ordinary ND > > or >>> 6lowpan's version, then they will need some third variety of > ND. I > do >>> not see why this is an issue for RPL to > address. It seems quite out >>> of scope. >>> > >>> > -Richard Kelsey >>> > _______________________________________________ >>> Roll mailing > list >>> > href="mailto:[email protected]";>[email protected] >>> > href="https://www.ietf.org/mailman/listinfo/roll"; target=_blank > >https://www.ietf.org/mailman/listinfo/roll >>> >> > >> >> > _______________________________________________ >> Roll mailing > list >> > href="mailto:[email protected]";>[email protected] >> > href="https://www.ietf.org/mailman/listinfo/roll"; target=_blank > >https://www.ietf.org/mailman/listinfo/roll > > _______________________________________________ > Roll mailing > list > > href="mailto:[email protected]";>[email protected] > > href="https://www.ietf.org/mailman/listinfo/roll"; target=_blank > >https://www.ietf.org/mailman/listinfo/roll > > _______________________________________________ > 6lowpan mailing > list > > href="mailto:[email protected]";>[email protected] > > href="https://www.ietf.org/mailman/listinfo/6lowpan"; target=_blank > >https://www.ietf.org/mailman/listinfo/6lowpan -- Zach Shelby, > Head of Research, Sensinode Ltd. http://zachshelby.org - My blog "On > the Internet of Things" http://6lowpan.net - My book "6LoWPAN: The Wireless > Embedded Internet" Mobile: +358 40 > 7796297 _______________________________________________ 6lowpan > mailing list > href="mailto:[email protected]";>[email protected] > href="https://www.ietf.org/mailman/listinfo/6lowpan"; target=_blank > >https://www.ietf.org/mailman/listinfo/6lowpan _______________________________________________ 6lowpan mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lowpan
