This read-only TimeStamp records the sysUpTime value the last time any entry was deleted from the ctCDPNeighborTable, and the description recommends polling it at least once per second, rebuilding the connectivity map with a fresh TimeFilter of 0 whenever it changes. An administrator relies on this to know precisely when to discard cached neighbor data and refetch the full table for an accurate connectivity map. For example, a network mapping application polls this value every second and, upon detecting a change, immediately re-walks the neighbor table from scratch to keep its topology diagram accurate.