6.5.1

Table Of Contents
Certificate Mode Description
VMware Certificate
Authority (default)
By default, the VMware Certificate Authority is used as the CA for ESXi host certificates. VMCA is the root
CA by default, but it can be set up as the intermediary CA to another CA. In this mode, users can manage
certificates from the vSphere Web Client. Also used if VMCA is a subordinate certificate.
Custom Certificate
Authority
Some customers might prefer to manage their own external certificate authority. In this mode, customers are
responsible for managing the certificates and cannot manage them from the vSphere Web Client.
Thumbprint Mode vSphere 5.5 used thumbprint mode, and this mode is still available as a fallback option for vSphere 6.0. Do
not use this mode unless you encounter problems with one of the other two modes that you cannot resolve.
Some vCenter 6.0 and later services might not work correctly in thumbprint mode.
Using Custom ESXi Certificates
If your company policy requires that you use a different root CA than VMCA, you can switch the certificate
mode in your environment after careful planning. The recommended workflow is as follows.
1 Obtain the certificates that you want to use.
2 Place the host or hosts into maintenance mode and disconnect them from vCenter Server.
3 Add the custom CA's root certificate to VECS.
4 Deploy the custom CA certificates to each host and restart services on that host.
5 Switch to Custom CA mode. See Change the Certificate Mode.
6 Connect the host or hosts to the vCenter Server system.
Switching from Custom CA Mode to VMCA Mode
If you are using custom CA mode and decide that using VMCA works better in your environment, you can
perform the mode switch after careful planning. The recommended workflow is as follows.
1 Remove all hosts from the vCenter Server system.
2 On the vCenter Server system, remove the third-party CA's root certificate from VECS.
3 Switch to VMCA mode. See Change the Certificate Mode.
4 Add the hosts to the vCenter Server system.
Note Any other workflow for this mode switch might result in unpredictable behavior.
Retaining Thumbprint Mode Certificates During Upgrade
The switch from VMCA mode to thumbprint mode might be necessary if you encounter problems with the
VMCA certificates. In thumbprint mode, the vCenter Server system checks only whether a certificate
exists and is formatted correctly, and does not check whether the certificate is valid. See Change the
Certificate Mode for instructions.
vSphere Security
VMware, Inc. 57