Question: how to find wwn number in esxi 6.5?
Answer: Connect to ESXi shell either via putty/SSH or DCUI (Direct Console User Interface) / server console. Run 'ls /proc/scsi/' and check the folder names: ...  Look for a folder like 'qla2xxx' – QLogic HBA, 'lpfc820' – Emulex HBA, 'bnx2i” – Brocade HBA; Run 'ls /proc/scsi/qla2xxx'.