Securing vCenter Server includes ensuring security of the host where vCenter Server is running, following best practices for assigning privileges and roles, and verifying the integrity of the clients that connect to vCenter Server.
vCenter Server Security Best Practices Following vCenter Server security best practices helps you ensure the integrity of your vSphere environment.
Verify Thumbprints for Legacy ESXi Hosts In vSphere 6 and later, hosts are assigned VMCA certificates by default. If you change the certificate mode to thumbprint, you can continue to use thumbprint mode for legacy hosts. You can verify the thumbprints in the vSphere Client.
Required Ports for vCenter Server The vCenter Server system must be able to send data to every managed host and receive data from the vSphere Client. To enable migration and provisioning activities between managed hosts, the source and destination hosts must be able to receive data from each other through predetermined TCP and UDP ports.