Comment # 22 on bug 1171770 from Rafael Fern�ndez L�pez

I have the impression that `net.ipv6.conf.all.forwarding = 0` being set by
`/etc/sysctl.d/70-yast.conf` has an impact here.

I did override this setting by creating a `/etc/sysctl.d/91-kubeadm.conf` file
with contents:

```
net.ipv4.ip_forward = 1
net.ipv6.conf.all.forwarding = 1
```

After rebooting the node, everything works fine. As Richard mentioned, removing
`/etc/sysctl.d/70-yast.conf` altogether and rebooting also makes the trick.

This makes me think that the override in `/usr/lib/sysctl.d/90-kubeadm.conf` is
not enough, it currently has:

```
# The file is provided as part of the kubernetes-kubeadm package
net.ipv4.ip_forward = 1
```

>From what I see, it should include `net.ipv6.conf.all.forwarding = 1` as well.
I cannot explain why this is happening in a better way right now though.