Re: IPv6 "is unreachable" route flapping

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

On Thu, Aug 22, 2019 at 07:53:52PM +0100, Roy Marples wrote:
> On 22/08/2019 19:00, Roy Marples wrote:
> > On 22/08/2019 18:58, Roy Marples wrote:
> > > On 22/08/2019 14:31, Roy Marples wrote:
> > > > On 22/08/2019 13:46, Paul Ripke wrote:
> > > > > > Does this attached patch help any?
> > > > > 
> > > > > This is for the client (dhcpcd running) side? And/or the
> > > > > server (rtadvd) side?
> > > > > I'll test it on a few machines and see what I see (I need to
> > > > > figure out a nice
> > > > > way of upgrading the Pi).
> > > > 
> > > > It's for the client.
> > > 
> > > OK, while that patch is of use, it doesn't really solve the problem
> > > and it's probably of limited use, but it does restore prior
> > > behaviour.
> > > 
> > > There are two problems in play - firstly I broke dhcpcd, patch
> > > attached to solve that.
> > 
> > Wups, old dhcpcd patch!
> > New one attached here :)
> 
> And to be clear, these are all client side patches.

There's one more call to rt_clonedmsg().

Something like the following?

--- a/sys/netinet/if_arp.c
+++ b/sys/netinet/if_arp.c
@@ -776,7 +776,7 @@ notfound:

                        arp_init_llentry(ifp, la);
                        sockaddr_in_init(&sin, &la->r_l3addr.addr4, 0);
-                       rt_clonedmsg(sintosa(&sin), ifp, rt);
+                       rt_clonedmsg(RTM_ADD, sintosa(&sin), NULL, ifp);
                }
        } else if (LLE_TRY_UPGRADE(la) == 0) {
                create_lookup = "lookup";

I have this running on a couple of machines that usually have flapping
v6 default routes. I'll see how it looks in the morning.

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