With local authentication enabled, the Gateway Enforcer appliance loses its connection with the server on which the Symantec Endpoint Protection Manager is installed. Therefore the Gateway Enforcer appliance authenticates a client locally.
To enable local authentication on a Gateway Enforcer appliance
In Symantec Endpoint Protection Manager, click Admin.
Select and expand the group of Gateway Enforcers appliances.
Under Tasks, click Edit Group Properties.
In the Settings dialog box, on the Advanced tab, check Enable Local Authentication.