The Do not allow sessions without one way CHAP machine setting should be configured correctly. If enabled then only those sessions that are configured for one-way CHAP may be established. If disabled then sessions that are configured for one-way CHAP or sessions not configured for one-way CHAP may be established. Note that if the "Do not allow sessions without mutual CHAP" setting is enabled then that setting overrides this one. Fix: (1) GPO: Computer Configuration\Administrative Templates\System\iSCSI\iSCSI Security\Do not allow sessions without one way CHAP (2) KEY: HKLM\Software\Policies\Microsoft\Windows\iSCSI\RequireOneWayCHAP