On Wed, Jul 20, 2016 at 03:13:05PM +0200, Lorenzo Colitti wrote: > On Wed, Jul 20, 2016 at 2:54 PM, David Lamparter <[email protected]> wrote: > > > - it's a bit unclear how an address/prefix's "source" next-hop is kept > > in association. The simplistic approach of adding a "PA source ipv6 > > address" for each of a host's configured addresses falls flat when > > more than 1 router advertises the same prefix, so I implemented it as > > a list -- however, my hack never removes entries off that. It should > > possibly have a copy of the PA's valid time? > > > > The way I thought of doing this would be to alternatively/additionally keep > a pointer from the default router that announced a given prefix (which does > have the link-local address of the router) to each address that was > configured from that prefix.
That turns nontrivial as soon as you have 4191 RIOs, especially if the router is trying to do walled gardens by sending its RAs with lifetime = 0 (as suggested in section 4.2.2 of pa-multihoming). > That way, when an address goes away you can scan the FIB and find > another router to associate with that prefix. [I assume "address goes away" meant "router goes away"] > As for lifetimes expiring, you would need to have somewhere to keep dummy > zero-lifetime default routes. It might be possible to do this in the FIB > itself by adding a special entry that doesn't ever match anything, or has > an infinite metric, or a different type... That sounds quite a bit more complicated than address-centric handling... we're 1:N for router['s LL address] to routes and also 1:N for router['s LL address] to prefixes, and then 1:N for prefix to derived addresses. I'd rather copy the prefix lifetime (either valid or preferred - probably former?) onto the same list entry where a configured address's RA source LL is also stored; that replicates only the last 1:N step... (So, for each address, in its list of RA sources that the prefix was seen from, there will be a potentially-distinct lifetime.) -David P.S.: Does anyone know the details of how Windows implements this? _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
