why rtsold ?

[Alan Somers]

On Mon, Oct 8, 2018 at 6:17 PM Victor Sudakov <vas at mpeks.tomsk.su> wrote:

> Kevin Oberman wrote:
> > > > > When running FreeBSD as an IPv6 host im SLAAC mode, is
> > > > > "rtsold_enable=YES" really necessary? I did not enable rtsold and
> IPv6
> > > > > still works fine only with
> > > >
> > > > rtsold is needed to write DNS server address from RDNSS RA option to
> > > > /etc/resolv.conf
> > > >
> > > > man rtsold
> > > > /-R
> > >
> > > On my test IPv6-only host, /etc/resolv.conf was successfully created
> > > without any explicit "rtsold_enable=YES".
> > >
> > > --
> > > Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
> > > 2:5005/49 at fidonet http://vas.tomsk.ru/
> > >
> > Remember that DHCPv6 can provide DNS server and other information even
> when
> > SLAAC is used for address configuration. If it is, it is possible to run
> > SLAAC without rtsold, but it may not prove stable as it is not possible
> to
>
> The case is that my IPv6 lab (actually a number of FreeBSD hosts in
> bhyve) does not have a DHCPv6 server. Still, the /etc/resolv.conf on
> IPv6-only hosts is successfully populated from the router.  The latter
> is running only rtadvd with the following config:
>
>
> bridge0:rdnss="2001:470:20::2,2001:4860:4860::8888,2001:4860:4860::8844":dnssl="
> sibptus.ru":
>
> Magick?
>

Not at all.  rtsol will populate /etc/resolv.conf just fine.  But it only
does it once.  rtsold is needed in case router info changes, or your
address times out.
-Alan