神明達哉 wrote: > > > > Who actually processes these router advertisements: the rtsold daemon > > or the kernel itself? > > > > Is this passage: > > > > 8.1.1.4. Plug and Play > > > > Most of the IPv6 stateless address autoconfiguration is implemented in > > the kernel. Neighbor Discovery functions are implemented in the kernel > > as a whole. Router Advertisement (RA) input for hosts is implemented > > in the kernel. Router Solicitation (RS) output for endhosts, RS input > > for routers, and RA output for routers are implemented in the > > userland. > > > > still correct? > > (from https://www.freebsd.org/doc/en/books/developers-handbook/ipv6.html) > > It's slightly outdated. "RA input for hosts" was originally limited > to what's described in RFC4862, but it's been extended over time. The > RFC4862-side (aka SLAAC) is still implemented in the kernel, but DNS > configuration options (RFC8106, although the FreeBSD implementation > may still only conform to RFC6106) are used in the user space. The > current trend seems to introduce more such high level config > information to RA, so I'd expect these will also be handled in the > user space. > > BTW, regarding the original topic of 'why rtsold', my understanding is > that its original motivation is to help hosts moving links. At least > at the time of development, there was no sophisticated detection > mechanism when a host is connected to a new link, so no one else could > send RS to get new network configuration information. rtsold monitors > link status and invokes new RS-RA exchanges when it detects a change > of the link status from off to on. Address lifetime expiration is not > usually an issue since routers are supposed to send RAs periodically > (with sufficiently short intervals to prevent accidental expiration); > and in any case (AFAIK) rtsold doesn't help that situation, as it > doesn't send RSes based on address lifetimes. > > Today, we now use DNS config information provided via RA in the user > space, so another role of rtsold is to reflect any changes to it while > the host is still connected to the same link. Routers are supposed > to advertise RAs with new information, but without rtsold (or > something equivalent) no one in the user space listens to those RAs to > apply the configuration change.
Thank you for the explanation. -- Victor Sudakov, VAS4-RIPE, VAS47-RIPN 2:5005/49@fidonet http://vas.tomsk.ru/ _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"