<p>I used the node.yaml and master.yaml files here: <a href="http://kubernetes.io/v1.1/docs/getting-started-guides/coreos/coreos_multinode_cluster.html" rel="nofollow">http://kubernetes.io/v1.1/docs/getting-started-guides/coreos/coreos_multinode_cluster.html</a> to create a multi-node cluster on 3 bare-metal machines running CoreOS. However, pods on different nodes can’t communicate with each other. I’d appreciate any pointers or suggestions. I’m at a loss.</p>

<p>I have three pods running rabbitmq:</p>

<pre><code>thuey:~ thuey$ kbg pods | grep rabbitmq
rabbitmq-bootstrap     1/1       Running   0          3h
rabbitmq-jz2q7         1/1       Running   0          3h
rabbitmq-mrnfc         1/1       Running   0          3h
</code></pre>

<p>Two of the pods are on one machine:</p>

<pre><code>kbd node jolt-server-3 | grep rabbitmq
thuey               rabbitmq-bootstrap      0 (0%)      0 (0%)      0 (0%)      0 (0%)
thuey               rabbitmq-jz2q7          0 (0%)      0 (0%)      0 (0%)      0 (0%)
</code></pre>

<p>And the other pod is on another machine:</p>

<pre><code>thuey:~ thuey$ kbd node jolt-server-4 | grep rabbitmq
thuey               rabbitmq-mrnfc          0 (0%)      0 (0%)      0 (0%)      0 (0%)
</code></pre>

<p>I can successfully ping from rabbitmq-bootstrap to rabbitmq-jz2q7:</p>

<pre><code>root@rabbitmq-bootstrap:/# ping 172.17.0.5
PING 172.17.0.5 (172.17.0.5) 56(84) bytes of data.
64 bytes from 172.17.0.5: icmp_seq=1 ttl=64 time=0.058 ms
64 bytes from 172.17.0.5: icmp_seq=2 ttl=64 time=0.035 ms
64 bytes from 172.17.0.5: icmp_seq=3 ttl=64 time=0.064 ms
64 bytes from 172.17.0.5: icmp_seq=4 ttl=64 time=0.055 ms
^C
--- 172.17.0.5 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3000ms
rtt min/avg/max/mdev = 0.035/0.053/0.064/0.010 ms
</code></pre>

<p>But I can't ping rabbitmq-mrnfc:</p>

<pre><code>root@rabbitmq-bootstrap:/# ping 172.17.0.8
PING 172.17.0.8 (172.17.0.8) 56(84) bytes of data.
From 172.17.0.2 icmp_seq=1 Destination Host Unreachable
From 172.17.0.2 icmp_seq=2 Destination Host Unreachable
From 172.17.0.2 icmp_seq=3 Destination Host Unreachable
From 172.17.0.2 icmp_seq=4 Destination Host Unreachable
^C
--- 172.17.0.8 ping statistics ---
5 packets transmitted, 0 received, +4 errors, 100% packet loss, time 4000ms
pipe 4
</code></pre>

<p>The guide you use don't include instructions for bare-metal machines. You need networking (e.g., flannel, calico) that implements Kubernetes's <a href="https://github.com/kubernetes/kubernetes/blob/4ca66d2aefa20c27b670b2fa890052daadc05294/docs/admin/networking.md" rel="nofollow">networking model</a>. You can check the <a href="https://github.com/kubernetes/kubernetes/blob/4ca66d2aefa20c27b670b2fa890052daadc05294/docs/getting-started-guides/README.md#table-of-solutions" rel="nofollow">table of solutions</a> for getting-started guides for different IaaS/OS/Network combinations.</p>
