Hi Jeroen, Am 29.09.2011 09:30, schrieb Jeroen Massar: > You do realize that the RIRs are providing exactly what you describe? :) > > - globally guaranteed unique (due to registry) large address prefixes > > Which is why from my information ULA-C has also been abandoned, as it > already is something that has already been resolved.
Ok, fine. We could use that _if_ the RIR policies allow unconnected use, but David Farmer pointed out that some policies may forbid that. I just figured out that RIPE's "IPv6 Address Allocation and Assignment Policy" says in 2.6: "To 'assign' means to delegate address space to an ISP or End User for specific use within the Internet infrastructure they operate." I'm not sure that one could denote the internal on-board network of a car as Internet infrastructure operated by ...?! Manufacturers also do not meet the LIR definition in 2.4, which is a precondition to get an initial allocation though (cf. 5.1.1 a)). Furthermore, where would a German manufacturer allocate the prefixes for its cars that are exported to Asia (at RIPE or APNIC)? So if we talk about ULA-Cs for traditional fixed networks you're right, but my use case was different. > What makes me wonder though, is why you would want to have different > prefixes in different locations that never ever ever will talk to each > other directly using those prefixes. As already said, maybe not in the car scenario but in others. However, history told us that address uniqueness is preferable in most cases. > At least I hope to never have a car that gets chatted up by the car next > to it to suddenly pull on the handbreak. Right, that's why we care about security in such an architecture. > Any car-2-car communication IMHO would happen with a different global > prefix, likely dynamically assigned to a 'gateway' function that has > proper security properties (call it a 'car rest interface or so). That Yep, correct. > security gateway will then relay commands to it's internal network. > That internal network can thus have the same prefix as the other car. > This thus allows one to simply take a random /48 (likely ULA) and > pre-program them in all the systems. Sure, you could do that. > Though it would be a cool idea, dynamically assigning addresses to > random components in a car where one actually needs to also then > maintain a registry of which components are where, will effectively mean > that there will be a DNS server too of sorts to map 'engine' to > 2001:db8:.....x and the left-mirror to 2001:db8:... Will be a lot of fun > to build I guess, but debugging that will be horrible and overly > complex. Then again, some times that is the fun in things right ;) The car on-board network requires usually real-time control guarantees, so having too much dynamics and several indirections/mappings is probably not so suitable. Regards, Roland -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
