| vMotion migrations in vSphere 6.0 and earlier transferred working memory and CPU state information in clear text over the vMotion network. As of vSphere 6.5, this transfer can be transparently encrypted using 256-bit AES-GCM with negligible performance impact.
vSphere enables encrypted vMotion by default as "Opportunistic", meaning that encrypted channels are used where supported, but the operation will continue in plain text where encryption is not supported.
For example, when vMotioning between two hosts, encryption will always be used. However, because 6.0 and earlier releases do not support this feature, vMotion from a 7.0 host to a 6.0 host would be allowed but would not be encrypted. If the encryption is set to "Required", vMotions to unsupported hosts will fail. This must be set to "Opportunistic" or "Required". |