If a physical network link is removed while being used by an iSCSI connection, the system may not notice that the iSCSI connection has failed until I/O is sent over the failed link.
Oracle FS Path Manager (FSPM) does not normally send I/O over non-optimized paths so Windows and FSPM can continue to report that the iSCSI non-optimized path is present and working although the underlying physical network link has failed.