<p><a href="https://i.stack.imgur.com/s614D.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/s614D.jpg" alt="Network is not ready error"></a></p>

<p>This happen's once or twice a week, without apply any commands. I just receive the alert that many of pods are down.</p>

<p>The settings of the cluster, created at least 40 days ago:</p>

<pre><code>gcloud container \
  clusters create "yourclustername" \
  --project "yourprojectname" \
  --zone "yourregion-zone" \
  --no-enable-basic-auth \
  --release-channel "regular" \
  --machine-type "e2-standard-2" \
  --image-type "COS" \
  --disk-type "pd-ssd" \
  --disk-size "20" \
  --metadata disable-legacy-endpoints=true \
  --scopes "https://www.googleapis.com/auth/devstorage.read_only","https://www.googleapis.com/auth/logging.write","https://www.googleapis.com/auth/monitoring","https://www.googleapis.com/auth/servicecontrol","https://www.googleapis.com/auth/service.management.readonly","https://www.googleapis.com/auth/trace.append" \
  --num-nodes "2" \
  --enable-stackdriver-kubernetes \
  --enable-ip-alias \
  --network "projects/yourprojectname/global/networks/yournetwork" \
  --subnetwork "projects/yourprojectname/regions/yourregion/subnetworks/yournetwork" \
  --default-max-pods-per-node "110" \
  --enable-autoscaling \
  --min-nodes "2" \
  --max-nodes "4" \
  --no-enable-master-authorized-networks \
  --addons HorizontalPodAutoscaling,HttpLoadBalancing,NodeLocalDNS,ApplicationManager \
  --enable-autoupgrade \
  --enable-autorepair \
  --max-surge-upgrade 1 \
  --max-unavailable-upgrade 0 \
  --enable-shielded-nodes
</code></pre>

<p>Node condition:</p>

<p><a href="https://i.stack.imgur.com/yo8Ty.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yo8Ty.png" alt="node condition"></a></p>

<p>I delete the pods with this error and GKE creates another, off course this is not a solution, at least 4 minutes of downtime. How to solve this? Do I need something like calico or flannel even on GKE?</p>

<p>Solved, <a href="https://docs.projectcalico.org/getting-started/kubernetes/managed-public-cloud/gke" rel="nofollow noreferrer">I enabled Calico</a> and it's CNI plugin solved the problem. GKE has built in support for it and the steps to enable it can be found here: <a href="https://cloud.google.com/kubernetes-engine/docs/how-to/network-policy" rel="nofollow noreferrer">https://cloud.google.com/kubernetes-engine/docs/how-to/network-policy</a></p>
