This policy setting determines if the server side SMB service is required to perform SMB packet signing. Enable this policy setting in a mixed environment to prevent downstream clients from using the workstation as a network server. This policy setting determines if the server side SMB service is required to perform SMB packet signing. Fix: (1) GPO: Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options!Microsoft network server: Digitally sign communications (always) (2) REG: HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\LanManServer\Parameters!requiresecuritysignature