> Ole Troan <mailto:[email protected]> > 22 February 2013 14:06 > Ray, > > [...] > >>> 2. Aren't we forgetting the first hop? >>> >>> Given a shared subnet/prefix/link with 2 CPE routers performing some >>> fancy new form of forwarding (based on PBR or SADR or whatever) >>> that is >>> also shared by existing host implementations, how will the routers >>> signal these new default route semantics to end hosts? >>> >>> Would we need a new prefix information option in ND? >>> >>> Would we need an extension to RFC 4191 Section 2.3 Route Information >>> Option to include (source prefix,destination prefix) routes? >>> >>> Would we need a new ICMPv6 redirect message to extend RFC2461 Section >>> 4.5 to include the possibility of (source,destination) redirects? >>> >>> >>> The beauty of this approach is that you don't need to signal anything >>> to the hosts for things to work properly. The hosts pick whatever >>> source address they choose and the network takes care of getting the >>> packet to the right exit. >>> >> Don't understand. Maybe I'm being really dumb. >> >> What about figure 2 of the Homenet Architecture? <fixed width> >> >> +-------+-------+ +-------+-------+ \ >> | Service | | Service | \ >> | Provider A | | Provider B | | Service >> | Router | | Router | | Provider >> +------+--------+ +-------+-------+ | network >> | | / >> | Customer | / >> | Internet connections | / >> | | >> +------+--------+ +-------+-------+ \ >> | IPv6 | | IPv6 | \ >> | Customer Edge | | Customer Edge | \ >> | Router 1 | | Router 2 | / >> +------+--------+ +-------+-------+ / >> | | / >> | | | End-User >> ---+---------+---+---------------+--+----------+--- | network(s) >> | | | | \ >> +----+-----+ +-----+----+ +----+-----+ +-----+----+ \ >> |IPv6 Host | |IPv6 Host | | IPv6 Host| |IPv6 Host | / >> | H1 | | H2 | | H3 | | H4 | / >> +----------+ +----------+ +----------+ +----------+ >> >> Figure 2 >> >> </fixed width> >> >> IPv6 Host H1 will receive RA messages from R1 and R2, and add them both >> to the default router list (RFC2461 6.3.6). >> >> IPv6 Host H1 will receive two PIO's, one each from R1 and R2, with >> autoconfiguration and on-link flags set, and configure /64 prefixes from >> both provider 1 and provider 2 (RFC 2461 4.6.2) and it will know these >> as being on-link. >> >> But IMHO there's no further AS number/provider information/upstream >> topology information coupled to these /64 prefixes. There might be a >> router-router interconnect LAN between R1 and R2, or there might not be. > > if there is no interconnect between R1 and R2, then the host has two > interfaces connected to two separate connections. then I can't see how > that can be solved in the network. my assumption is that all homenet routers > must be connected (I see I haven't stated that anywhere, but that should be > added). > >> How will the host H1 know to associate source address prefixes from >> provider2 with router2 for off link destinations e.g. to a Provider2/56 >> or Provider2/32? > > in your case it will RFC6724, rule 5.5 Doh! Thanks. Agree it'll work, but possibly not for all current implementations. > <snip> >>> They wouldn't participate in any routing protocol with the ISP. We >>> don't currently have any other mechanism for learning external routes, >>> but when we do we can simply treat them in the same way. >>> >>> Does this not work for some reason? >>> >> No problem, but why worry about it now if it greatly increases the >> complexity? >> >> draft-ietf-v6ops-6204bis-12 effectively limits information in Homenet to >> simple default routes per provider only. >> >> W-3: Absent other routing information, the IPv6 CE router MUST use >> Router Discovery as specified in [RFC4861] to discover a >> default router(s) and install default route(s) in its routing >> table with the discovered router's address as the next hop. >> >> WPD-7: By default, an IPv6 CE router MUST NOT initiate any dynamic >> routing protocol on its WAN interface. > > but 6204 does support more specific routes in RAs (RFC4191?)
Yes, on the LAN interface in requirement L3, purely for advertising ULA and delegated prefixes. RFC4191 isn't excluded on the WAN for learning upstream prefixes (from a walled garden), but it's also not explicitly required either. Perhaps it should be. I'm not 100% convinced of the use case though. Currently only default route(s) are mentioned on the WAN interface. <snip> _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
