A default certificate is generated automatically for the ESXi host during installation. Because the certificate for the ESXi host was self-generated, it has not been signed and will not be given a trusted status when attempting to communicate with other servers and clients. Other network devices might not allow communication with the ESXi host until it is certified by a well-known CA. X.509 certificates are supported over SSL connections for the encrypted session.
NOTE: When replacing the default certificate of the ESXi host, if the vCenter Server stops managing the host, check whether the ESXi host has Verify Certificates enabled. If this is the case, reconnect the ESXi host to the vCenter Server using the vSphere Client.
The steps to add a CA-signed certificate are as follows:
Step 1. Log in to the ESXi host over SSH using Putty.
Step 2. Change the directories to /etc/vmware/ssl, and backup the certificate files:
# mv rui.crt rui.cert.orig
# mv rui.key rui.key.orig
Step 3. Go to the location where the new authenticated certificate rui.crt and key file rui.key are located and copy the certificate files to the directory /etc/vmware/ssl.
Step 4. Either restart the services using
# services.sh restart
or reboot the ESXi host.