Re: IPv6 "is unreachable" route flapping

[Paul Ripke <stix%stix.id.au@localhost>]

On Mon, Mar 09, 2020 at 10:42:42AM +0000, Roy Marples wrote:
> On 09/03/2020 10:28, Paul Ripke wrote:
> > Time has passed, and I'm now running netbsd-9 on the orange pi, and
> > on the amd64 router. I still see these issues with IPv6 route flaps.
> > 
> >  From the arm side:
> > 
> > Mar  9 20:52:20 thing1 dhcpcd[292]: emac0: Router Advertisement from fe80::52e5:49ff:fea6:f5d8
> > Mar  9 20:52:20 thing1 dhcpcd[292]: emac0: fe80::52e5:49ff:fea6:f5d8: no longer a default router
> 
> Well, that's pretty telling.
> dhcpcd received a RA with a router lifetime of zero.
> It's not that the route is flapping, it's the router saying it's no longer a
> default router and should not be used.
> dhcpcd is just doing what it's told.
> 
> The rest of the debug is irrelevant at this point.
> 
> Is there anything on your router restarting rtadvd as that would trigger the above?

Nothing restarting it, afaik. I do have a /etc/ppp/dhcp6c-script:

----
#!/bin/ksh

IP=$(ifconfig pppoe0 | awk '/inet6/ {print $2}' | cut -d / -f 1)
route change -inet6 default "$IP" || route add -inet6 default "$IP"
sleep 2 && /etc/rc.d/rtadvd reload
----

And /etc/rtadvd.conf:

----
alc0:\
        :maxinterval#300:\
        :rltime#3600:
----

I've commented out the SIGHUP, I forget why I added that - lost to the
mists of time. Alternately, I see rtadvd has a -C option, but that sounds
wrong. I'll see what happens with it commented out.

Thanks!
-- 
Paul Ripke
"Great minds discuss ideas, average minds discuss events, small minds
 discuss people."
-- Disputed: Often attributed to Eleanor Roosevelt. 1948.