This read-only DateAndTime object reports when the last vPC peer-keepalive message was sent, containing a special all-zero-based value if a message has never been sent. Administrators use it to confirm the keepalive mechanism is actively transmitting on schedule, which helps distinguish a truly idle/never-configured keepalive from one that has simply stopped sending. For example, seeing this timestamp stuck in the past despite an expected keepalive interval would indicate the local switch has stopped sending keepalive messages, worth investigating even if overall status hasn't yet flagged a failure.