This object determines whether a Fibre Channel route is retained or removed from the route table when its output interface goes operationally down, defaulting to retain(2). An admin sets this to remove(1) for routes that should be purged automatically on a link failure rather than left stale in the table. For example, setting this to remove(1) on a route over a redundant ISL ensures the table cleans itself up immediately if that link fails, rather than requiring manual cleanup.