<p>I have a single master cluster with 3 worker nodes. The master node has one network interface of 10Gb capacity and all worker nodes have a 40Gb interface. They are all connected via a switch.</p>
<p>I'd like to know if this might create a bottleneck if the data between nodes have to pass through the master node?</p>
<p>In general, I like to understand the communication flow between worker nodes. For instance, a pod in node1 sends data to a pod in node2, does the traffic go through the master node? I have seen the architecture diagram on the Kubernetes docs and it appears to be the case:</p>
<p><a href="https://i.stack.imgur.com/RUasH.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RUasH.png" alt="enter image description here" /></a>
source: <a href="https://kubernetes.io/docs/concepts/overview/components/" rel="nofollow noreferrer">https://kubernetes.io/docs/concepts/overview/components/</a></p>
<p>If this is the case, it is possible to define a control plane network separate from the data plane by possibly adding another interface to worker nodes?</p>
<p>Please note that this is a bare-metal on-prem installation with OSS Kubernetes v1.20.</p>

Muzammil
<blockquote>
<p>For instance, a pod in node1 sends data to a pod in node2, does the traffic go through the master node?</p>
</blockquote>
<p>No. Kubernetes is designed with a flat network model. If Pod on node A send a request to Pod on node B, the inter-node traffic is directly from node A to node B as they are on the same IP network.</p>
<p>See also <a href="https://kubernetes.io/docs/concepts/cluster-administration/networking/#the-kubernetes-network-model" rel="nofollow noreferrer">The Kubernetes network model</a></p>
