Hello Ray, Thanks for the comments, and for making these experimentations.
Comments inline, > OK Got it. Thanks. > > Another question. I've been testing with smaller prefixes than that required > to configure the Homenet. > > Is behavior defined for that situation? In the past version of the PA draft, these considerations were part of the draft. Since last IETF, PA and HNCP drafts were split into 3 different drafts. DNCP, HNCP, and PA. The PA one is now Homenet agnostic, and because no behavior would be better in *all* cases where the algorithm is used, the behavior is left as implementation/configuration specific. It is now HNCP’s role to have this kind of considerations. And for now, the behavior is undefined. > > i.e. I am delegating a /60 but I have 9 interfaces (with 4 common) = 6 > prefixes to assign in Homenet. > > Theoretically that should fit. And it does > > Delegating router gives out a lease for 2001:6d8 :67d2 :1f0::/60 > > So Homenet 1 has > 2001:6d8:67d2:1f9:16cc:20ff:fe8a:15c4/64(common with Homenet 2) > 2001:6d8:67d2:1ff:16cc:20ff:fe8a:15c4/64 > 2001:6d8:1f15:62e:16cc:20ff:fe8a:15c4/64 (WAN) > > Homenet 2 has > 2001:6d8:67d2:1f9:16cc:20ff:fe8a:15d6/64 (common with Homenet 1) > 2001:6d8:67d2:1f5:16cc:20ff:fe8a:15d6/64 > 2001:6d8:67d2:1f7:16cc:20ff:fe8a:15d6/64 (common with Homenet 3) > > Homenet 3 has > > 2001:6d8 :67d2 :1f7:16cc:20ff:fe8a:154c/64 (common with Homenet 2) > 2001:6d8 :67d2 :1f3:16cc:20ff:fe8a:154c/64 > 2001:6d8 :67d2 :1f2:16cc:20ff:fe8a:154c/64 > > > Now if I reduce the lease to a /62 I get problems (as expected) > > lease granted is 2001:6d8 :67d2 :130::/62 > > 2001:6d8 :67d2 :131:b834::89fe/80(common with Homenet 2) > 2001:6d8 :67d2 :131:2eb6::9bb2/80 > 2001:6d8:1f15:62e:16cc:20ff:fe8a:15c4/64 (WAN) > > Homenet 2 has > 2001:6d8 :67d2 :131:b834::e8a9/80 (common with Homenet 1) > 2001:6d8 :67d2 :131:2e46::a68a/80 > 2001:6d8 :67d2 :130:16cc:20ff:fe8a:15d6/64 (common with Homenet 3) > > Homenet 3 (powered on first) has > > 2001:6d8 :67d2 :132:16cc:20ff:fe8a:154c/64 > 2001:6d8 :67d2 :133:16cc:20ff:fe8a:154c/64 > 2001:6d8 :67d2 :130:16cc:20ff:fe8a:154c/64 (common with Homenet 2) > > > So this looks like a pathological case (as expected). > > Is it defined what should happen in this case? > > Should a prefix be split, or simply as many /64's as possible be assigned? RFC7368 section 3.4.1 states that /64 should not be split. The implementation (hnet) does not behave like that. The prefix is split. And it works fine with most clients. It is a tradeoff between having N links with no prefix at all, or N+1 links with a /80. > > If it were theoretically possible to discover that inter-router links were > actually point to point links, should these be assigned /127's or the /80's > instead? > That would preserve more /64's for end user systems. One mechanism could be > to check the ND cache for other link local entries, other than other Homenet > speaking routers? In order to assign a /80, you have to brake one single /64. Giving you 2^16 smaller prefixes (You could even use a /90, it does not make difference as soon as you go further /64). I don’t see what using /127’s would really bring. But this is HNCP consideration, not PA. PA algorithm allows you to use any prefix length. In the latest implementation, PA code is used for both prefix and address (/128) assignment. > > I've also tried to add additional /62 prefixes to the DHCP PD server (fake > ISP router) DHCPD config, but the Homenet either doesn't request these, or > the ISC code isn't assigning them. > The homenet is thus only using a single lease, rather than concatenating > multiple small leases. > > That to me would either simulate the situation where multiple small leases > were available from one ISP for utilization to number links from multiple > prefixes, or a make before break renumbering event was upcoming. > > Either way I'd expect the Homenet to somehow grab these additional leases if > it had run out in the original PD assignment space, or to prepare for > renumbering by assigning dual prefixes per link. > > Is there anything to define in your draft? In Homenet model, each provided prefix is attached to an uplink. It does not mean that one ISP has to provide a single prefix, it could provide multiple (with prefix coloring for instance). *But*, it means that each prefix has a different purpose, and that ultimately each link should be numbered with prefixes from each DP. It would be technically possible to do what you are saying. But in practice, ISP’s should/must provide /56. I believe that in some situations, it might not be that simple. But I also believe that those who are able to give you multiple /62s should try harder, work on their aggregation, and provide one single bigger prefix. It’s not like we are missing addresses. Regards, - Pierre _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
