Last Active, Last Seen, and Lastknownipaddress

Last Active: - Displays the timestamp when a device was last actively involved in a call.  

Last seen and Last Seen Summary: - Displays the timestamp when the last time the device reported its location, or the device registered. Last Seen also known as Last registered.

Lastknownipaddress: Last known IP address of phone.

Lastknownucm :-  Last known Unified Communications Manager this phone registered to.

*Last Registered/Last Seen and Last Active fields are introduced in UCM 12.x and these fields are updated once CUCM Database maintenance timer is triggered.

**This feature is enabled by default. Administrators can choose to enable or disable this feature in the UCM->Service Parameter Configuration screen at System > Service Parameters. The Phone Status Update Window parameter of the Cisco Database Layer Monitor (Active) service can be assigned values from 0 to 24 hours.

If this feature is disabled, the Last Registered and the Last Active columns values will be blank.