why rtsold ?

[alan somers]

On Sat, Sep 29, 2018, 11:24 PM Victor Sudakov <vas at mpeks.tomsk.su> wrote:

> Alan Somers 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
> > >
> > > fconfig_re0=""
> > > ifconfig_re0_ipv6="inet6 accept_rtadv"
> > >
> > > What would be the point of enabling rtsold then?
> >
> > The router may send a router advertisement whenever it wants.  That's why
> > your machine seems to work even without rtsold.  However, SLAAC addresses
> > expire after a certain amount of time.  rtsold will ask the router for a
> > new advertisement before your address expires.  You aren't guaranteed to
> > have problems if you don't run rtsold, but you aren't guaranteed not to
> > have problems if you don't.  Best to let it run.
>
> I see the point but who on earth sent the initial router solicitation
> on boot if I never enabled rtsold?
>
> I have not found rtsold in /etc/rc.d/netif or similar startup script.
>
> --
> Victor Sudakov,  VAS4-RIPE, VAS47-RIPN
> 2:5005/49 at fidonet http://vas.tomsk.ru/


The rtsol command will send a single router solicitation. It's probably
getting invoked on startup. Or, you might've just gotten lucky and heard an
unsolicited router advertisement.