This read-write object identifies whether a routing table entry represents a directly connected destination or a remote one reached through another system, and setting it to invalid(2) effectively removes that destination-to-route association. An admin managing static routes can use this specifically to deactivate a route without necessarily deleting the row outright, though whether the underlying agent physically removes an invalidated entry from the table is implementation-specific. For example, an admin decommissioning a static route would set this field to invalid(2) rather than assuming the row disappears immediately, and should verify separately whether the agent actually purges it.