<p>when I'm running the command:</p>

<pre><code>gcloud beta compute instance-groups managed rolling-action start-update gke-playground-pool-test-1-420d5b80-grp  --version template=elk-pool-template-us-west1-3 --zone us-west1-b --max-surge 1 --max-unavailable 1 --type opportunistic --force
</code></pre>

<p>I'm getting the following error:</p>

<pre><code>ERROR: (gcloud.beta.compute.instance-groups.managed.rolling-action.start-update) Could not fetch resource:
 - Invalid value for field 'resource.instanceTemplate': ''. Unable to create an instance from instanceTemplate elk-pool-template-us-west1-3 in zone us-west1-b:
        Invalid value for field 'instance.networkInterfaces[0].accessConfigs[0].natIP': The specified external IP address 'xx.xxx.xxx.xx' is not reserved in region 'us-west1'.
</code></pre>

<blockquote>
  <p>The specified external IP address 'xx.xxx.xxx.xx' is not reserved in 
  region 'us-west1' </p>
</blockquote>

<p>The issue you have described is usually caused by a template that tries to claim unreserved External IP. To make those IP's available you have to first reserve them by buying it in GCP. You can find more about External IP addresses <a href="https://cloud.google.com/compute/docs/ip-addresses/" rel="nofollow noreferrer">here.</a> </p>

<p>If the reserved IP address is available, you can use it. In another case, the service will allocate External IP which will be available at that moment. You can find more about reserving IP addresses <a href="https://cloud.google.com/compute/docs/ip-addresses/reserve-static-external-ip-address" rel="nofollow noreferrer">here</a>. </p>
