A cluster VIP for a Nutanix cluster is very helpful to always have the same IP address to reach a Nutanix cluster, even when 1 node has failed or is in maintenance. This same principle is useful when you have deployed a scale-out Prism Central Instance.

Why should you bother about a cluster VIP with a single-node Prism Central instance. Recently I found a reason. And I am willing to share that with you as is not listed in the documentation.

Nutanix Central Registration

When you are going to use Nutanix Central (NC), and all prerequisites are fulfilled, you are able to register your domain to Nutanix Central. To register a domain, you need the Prism Central UUID and the location. Following the UI of NC, an API key is generated and you have to download this key.

After downloading the API key, you have to browse to the Admin Center of PC, where you are able to register the PC instance to Nutanix Central.

When registering to Nutanix Central, you have to upload your downloaded API key. (The download is called trust_bundle, so don’t be confused about terminology.)

According to the documentation this registration can take upto 15 minutes. In our case, without a Prism Central VIP, we waited for over 40 minutes, created a case with Nutanix support, and while waiting the task timed out after approximately 60 minutes. It turned out that this registration process is expecting a cluster VIP, even when it is ‘just’ a single PC instance.

After adding a Virtual IP in the settings of Prism Central, the registration of the PC with Nutanix Central took only a few seconds.

We asked for an update of the documentation at Nutanix side, but until they added this, you should use this blog. 😉

20251006 – UPDATE

With the release of AOS 7.3.1, this issue seems to be fixed according to the release notes.