Joerg Sonnenberger <jo...@bec.de> wrote: >On Wed, Apr 21, 2021 at 02:21:51AM -0700, John Nemeth wrote: >> On Apr 20, 21:13, Joerg Sonnenberger wrote: >> } On Wed, Apr 21, 2021 at 12:54:36AM +0700, Robert Elz wrote: >> } > It seems as if what is happening, is that the router is sending RA's with >> } > the source-link addr option, which isn't being added to the neighbour >> } > cache. >> } > >> } > Then NetBSD is doing a NS to discover the address it ignored from the RA, >> } > but instead of replying with a ND as would perhaps be expected, the >> router >> } > is simply sending another RA (containing the relevant addr info, which >> would >> } > answer the NS if processed). >> } >> } I'm not entirely sure that the behavior of sending a RA as "answer" to a >> } NS is valid under RFC 4861, but I also don't understand why the existing >> } code (nd6_rtr_cache) doesn't cover this. That would be a good place to >> } debugging this. >> } >> } > I'd suggest putting RA processing back into the kernel to avoid this kind >> } > of issue. >> } >> } Except of course that it introduces back all the reasons for why it was >> } removed in first place and ignores that it shouldn't happen. >> >> RA processing is fundamental to the operation of IPv6. Removing >> it was extremely stupid and not well thought out. The decision >> should be reverted. I didn't have a problem with a sysctl to >> disable it, but I have a huge problem with removing it completely. > >RA processing is not time-sensitive. It doesn't require any special >interfaces. A correct and useful implementation requires non-trivial >policy decisions. There are a lot of reasons for why it should not be >part of the kernel and very few of why it should be. In fact, other >systems never implemented it in the kernel or have similary moved it for >pretty much the same reason.
One subsystem that made use of RA processing being in the kernel is MobileIPv6, it used notifications from the kernel to work out that a node has moved, I did get a suggestion from roy@ on an alternative way to do this but haven't implemented it yet. Think we need to make dhcpcd work with rump if it is the only way to do RA processing.
