This read-only value reports the sysUpTime timestamp at which this Virtual Interface last entered its current operational state, reading zero if that state was entered before the last reinitialization of the local management subsystem. An admin uses it to determine how long a VI has been in its present up or down state, useful for correlating a VI flap with other events. For example, a csOrionVIfLastChange value that is very recent relative to sysUpTime on a VI expected to have been stable for weeks signals the VI recently transitioned state, worth investigating.