On a NetScaler SDX service virtual machine, the status of the NetScaler VPX instance appears as DOWN or OUT OF SERVICE. However, the NetScaler VPX instance is working and is processing network traffic.

When the GUI for that particular NetScaler VPX instance is opened, the HTTP access fails but HTTPS access is successful.

In the NetScaler VPX instance, the Secure access only option is enabled on the NetScaler IP (NSIP) address.
Path: System > Network > IPs.

To resolve this issue, configure the Management Service (SDX GUI) to communicate with NetScaler over HTTPS.

Select Configuration > System > System Settings > Change System Settings to configure this option on SDX GUI

Problem Cause

On the NetScaler SDX service virtual machine, the Management Service to NetScaler Communication option is set to HTTP.

Note: VM state showing in "Out of Service" or Yellow state can also occur if you have manually changed the nsroot password from the VPX instance level. It is recommended to change the nsroot password for VPX from SVM level by editing the VPX and binding a new admin profile with the updated password. This way SVM will not lose connectivity with the VPX.